Ubuntu 11.10 Wubi installation error: "prefix" is not set

The "No wubildr" is not an error, it's a diagnostic. It just means there was no wubildr on /dev/sda1. It looks on every partition until it finds it. As long as it finds it afterwards then that's normal.

The 'prefix' not set error is an error (it says it's an error) but it is always issued on all wubi installs every time they boot and is not the cause or reason for any boot problems.

More likely the black screen is due to graphics card issues. It used to be that only nvidia/ati graphics cards gave problems but with many of the newer intel cards there are black screens on boot (sometimes it's the backlight only that's off, but other times it's completely off).
Please specify:
Computer brand, model, graphics card (more than one if you have them).
Thanks

Its an assembled desktop..
Pentium D processor 2.67Ghz, ACPI x86 Based PC
2GB RAM
ATI radeon Xpress 200 series 1GB graphics card

What do you suggest i do? Cant i install Ubuntu through Wubi or is it that i cant run Ubuntu at all??

This doesn't sound like a Wubi-specific issue, but I need some more info.
1. That graphics card seems to be supported. When you get the 'black screen' does it seem like the hard drive is working or is it just sitting there?
2. Did you install by downloading and running wubi.exe alone? Or did you install from a CD or download the CD ISO manually?

Something you can do (to make sure your computer is compatible) is to download the desktop CD ISO and burn it to CD or create a bootable USB (as explained here: http://www.ubuntu.com/download/ubuntu/download ). Then boot your computer from the CD/USB, select "Try Ubuntu". This will boot to a Ubuntu desktop environment (without making any changes to your computer). This will ensure that it's compatible.

Forgive me for being so naive but it is not just a black screen, its a black screen with a blinking cursor..so is it some kind of a terminal!?

1.The hard drive light(i'm guessing the green one, stays on)...the CPU light(the orange one) doesnt flicker at all on the black screen
2.Yes, i just downloaded and ran wubi.exe with the --32bit argument

I will try the CD ISO as soon as possibe

Okay - if the hard drive light is going then it's probably a graphics issue. You can try booting with the nomodeset option: http://ubuntuforums.org/showthread.php?t=1613132 (post #8 is for wubi specific FIRST boot). I think this still applies to you, so you would use Method #2.

If you're booting from the CD and you also get a black screen, then post#1 shows how to override boot options on the CD

I made a mistake in post #5... i was confused about which indicator was the hard-disk light...figured out it was the opposite....

CORRECTION: the hard drive light flickers for a second when i reach the black screen and then remains off.

So it must be a hard drive issue?
Still, i tried method #2 in the thread and added "nomodeset" after "quiet splash"....it didnt work ...apologies for my mistake

It's unlikely a (mechanical) hard drive issue. We need to just gather some info and see if the answer becomes clear. There can be a number of things that interfere.

Did you try booting the Ubuntu CD yet? That will show whether Ubuntu is compatible. Then you can run the bootinfoscript (http://bootinfoscript.sourceforge.net/ )which will provide some decent info on the partitions on your drive. You can pastebin the results and post the pastebin link back here.
Thanks

I made an Ubuntu 11.10 boot CD and chose the "try ubuntu without installing" option... the same thing happens....black screen with a blinking cursor and a frozen keyboard.
In fact the black screen sometimes appeared even before i got the boot options menu.
I even tried booting the live cd with the nomodeset option but the result was unchanged.

I had a Knoppix 6.2 live DVD which worked on my PC...i ran the bootinfoscript....here are the results :

                  Boot Info Script 0.61 [1 April 2012]

============================= Boot Info Summary: ===============================

 => Windows is installed in the MBR of /dev/sda.

sda1: __________________________________________________________________________

    File system: ntfs
    Boot sector type: Windows Vista/7: NTFS
    Boot sector info: According to the info in the boot sector, sda1 starts
                       at sector 2048. But according to the info from fdisk,
                       sda1 starts at sector 63. The info in boot sector on
                       the starting sector of the MFT is wrong. According to
                       the info in the boot sector, sda1 has 204799 sectors,
                       but according to the info from fdisk, it has 1984
                       sectors.
    Operating System:
    Boot files: /bootmgr /Boot/BCD /wubildr

sda2: __________________________________________________________________________

    File system: ntfs
    Boot sector type: Windows Vista/7: NTFS
    Boot sector info: According to the info in the boot sector, sda2 starts
                       at sector 206848. But according to the info from
                       fdisk, sda2 starts at sector 2048. The info in boot
                       sector on the starting sector of the MFT is wrong.
                       According to the info in the boot sector, sda2 has
                       63272959 sectors, but according to the info from
                       fdisk, it has 204799 sectors.
    Operating System: Windows 7
    Boot files: /Windows/System32/winload.exe /wubildr
                       /ubuntu/winboot/wubildr /wubildr.mbr
                       /ubuntu/winboot/wubildr.mbr /ubuntu/disks/root.disk
                       /ubuntu/disks/swap.disk

sda2/Wubi: _____________________________________________________________________

    File system: ext3
    Boot sector type: -
    Boot sector info:
    Operating System: Ubuntu 11.10
    Boot files: /etc/fstab

sda3: __________________________________________________________________________

    File system: ntfs
    Boot sector type: Windows Vista/7: NTFS
    Boot sector info: According to the info in the boot sector, sda3 starts
                       at sector 63479808. But according to the info from
                       fdisk, sda3 starts at sector 206848. According to the
                       info in the boot sector, sda3 has 69631999 sectors,
                       but according to the info from fdisk, it has 63272959
                       sectors.
    Operating System:
    Boot files: /wubildr

sda4: __________________________________________________________________________

    File system: ntfs
    Boot sector type: Windows Vista/7: NTFS
    Boot sector info: According to the info in the boot sector, sda4 starts
                       at sector 133114590. But according to the info from
                       fdisk, sda4 starts at sector 63479808. According to
                       the info in the boot sector, sda4 has 20482874
                       sectors, but according to the info from fdisk, it has
                       92819631 sectors.
    Operating System:
    Boot files: /wubildr

============================ Drive/Partition Info: =============================

Drive: sda _____________________________________________________________________

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x0cd70cd6

Partition Boot Start Sector End Sector # of Sectors Id System

/dev/sda1 63 2,047 1,985 42 SFS
/dev/sda2 * 2,048 206,847 204,800 42 SFS
/dev/sda3 206,848 63,479,807 63,272,960 42 SFS
/dev/sda4 63,479,808 156,299,439 92,819,632 42 SFS

"blkid" output: ________________________________________________________________

Device UUID TYPE LABEL

/dev/cloop0 iso9660 KNOPPIX_FS
/dev/sda1 6C7CAC9F7CAC6614 ntfs
/dev/sda2 E6A8C1FBA8C1CA6F ntfs
/dev/sda3 9A30481B304800AD ntfs New Volume
/dev/sda4 8E6E2DC06E2DA1C7 ntfs
/dev/sda5 C2B83943B839376F ntfs

================================ Mount points: =================================

Device Mount_Point Type Options

/dev/cloop /KNOPPIX iso9660 (ro,relatime)
/dev/sr0 /mnt-system iso9660 (ro,relatime)

============================= sda2/Wubi/etc/fstab: =============================

--------------------------------------------------------------------------------
# UNCONFIGURED FSTAB FOR BASE SYSTEM
--------------------------------------------------------------------------------

================= sda2/Wubi: Location of files loaded by Grub: =================

           GiB - GB File Fragment(s)

   0.238567352 = 0.256159744 boot/initrd.img-3.0.0-12-generic 40
   0.228386879 = 0.245228544 boot/vmlinuz-3.0.0-12-generic 20
   0.228386879 = 0.245228544 vmlinuz 20

======================== Unknown MBRs/Boot Sectors/etc: ========================

MFT Sector of sda1

00000000 46 49 4c 45 30 00 03 00 ea 22 10 00 00 00 00 00 |FILE0...."......|
00000010 01 00 01 00 38 00 01 00 a0 01 00 00 00 04 00 00 |....8...........|
00000020 00 00 00 00 00 00 00 00 06 00 00 00 00 00 00 00 |................|
00000030 02 00 87 8d 00 00 00 00 10 00 00 00 60 00 00 00 |............`...|
00000040 00 00 18 00 00 00 00 00 48 00 00 00 18 00 00 00 |........H.......|
00000050 ce 7a 57 ac 42 bc cb 01 ce 7a 57 ac 42 bc cb 01 |.zW.B....zW.B...|
*
00000070 06 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000080 00 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 |................|
00000090 00 00 00 00 00 00 00 00 30 00 00 00 68 00 00 00 |........0...h...|
000000a0 00 00 18 00 00 00 03 00 4a 00 00 00 18 00 01 00 |........J.......|
000000b0 05 00 00 00 00 00 05 00 ce 7a 57 ac 42 bc cb 01 |.........zW.B...|
000000c0 ce 7a 57 ac 42 bc cb 01 ce 7a 57 ac 42 bc cb 01 |.zW.B....zW.B...|
000000d0 ce 7a 57 ac 42 bc cb 01 00 40 00 00 00 00 00 00 |.zW.B....@......|
000000e0 00 40 00 00 00 00 00 00 06 00 00 00 00 00 00 00 |.@..............|
000000f0 04 03 24 00 4d 00 46 00 54 00 00 00 00 00 00 00 |..$.M.F.T.......|
00000100 80 00 00 00 48 00 00 00 01 00 40 00 00 00 01 00 |....H.....@.....|
00000110 00 00 00 00 00 00 00 00 3f 00 00 00 00 00 00 00 |........?.......|
00000120 40 00 00 00 00 00 00 00 00 00 04 00 00 00 00 00 |@...............|
00000130 00 00 04 00 00 00 00 00 00 00 04 00 00 00 00 00 |................|
00000140 21 40 55 21 00 01 f4 88 b0 00 00 00 50 00 00 00 |!@U!........P...|
00000150 01 00 40 00 00 00 05 00 00 00 00 00 00 00 00 00 |..@.............|
00000160 01 00 00 00 00 00 00 00 40 00 00 00 00 00 00 00 |........@.......|
00000170 00 20 00 00 00 00 00 00 08 10 00 00 00 00 00 00 |. ..............|
00000180 08 10 00 00 00 00 00 00 21 01 54 21 21 01 fe fd |........!.T!!...|
00000190 00 00 01 00 00 50 87 8d ff ff ff ff 00 00 00 00 |.....P..........|
000001a0 00 00 04 00 00 00 00 00 21 40 55 21 00 01 f4 88 |........!@U!....|
000001b0 b0 00 00 00 50 00 00 00 01 00 40 00 00 00 05 00 |....P.....@.....|
000001c0 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 |................|
000001d0 40 00 00 00 00 00 00 00 00 20 00 00 00 00 00 00 |@........ ......|
000001e0 08 10 00 00 00 00 00 00 08 10 00 00 00 00 00 00 |................|
000001f0 21 01 54 21 21 01 fe fd 00 00 01 00 00 50 02 00 |!.T!!........P..|
00000200
MFT Sector of sda2

00000000 46 49 4c 45 30 00 03 00 34 39 51 5f 00 00 00 00 |FILE0...49Q_....|
00000010 01 00 01 00 38 00 01 00 a8 01 00 00 00 04 00 00 |....8...........|
00000020 00 00 00 00 00 00 00 00 07 00 00 00 00 00 00 00 |................|
00000030 8d 01 00 00 00 00 00 00 10 00 00 00 60 00 00 00 |............`...|
00000040 00 00 18 00 00 00 00 00 48 00 00 00 18 00 00 00 |........H.......|
00000050 28 da 9d c0 42 bc cb 01 28 da 9d c0 42 bc cb 01 |(...B...(...B...|
*
00000070 06 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000080 00 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 |................|
00000090 00 00 00 00 00 00 00 00 30 00 00 00 68 00 00 00 |........0...h...|
000000a0 00 00 18 00 00 00 03 00 4a 00 00 00 18 00 01 00 |........J.......|
000000b0 05 00 00 00 00 00 05 00 28 da 9d c0 42 bc cb 01 |........(...B...|
000000c0 28 da 9d c0 42 bc cb 01 28 da 9d c0 42 bc cb 01 |(...B...(...B...|
000000d0 28 da 9d c0 42 bc cb 01 00 00 d0 05 00 00 00 00 |(...B...........|
000000e0 00 00 d0 05 00 00 00 00 06 00 00 00 00 00 00 00 |................|
000000f0 04 03 24 00 4d 00 46 00 54 00 00 00 00 00 00 00 |..$.M.F.T.......|
00000100 80 00 00 00 50 00 00 00 01 00 40 00 00 00 01 00 |....P.....@.....|
00000110 00 00 00 00 00 00 00 00 ff 5c 00 00 00 00 00 00 |.........\......|
00000120 40 00 00 00 00 00 00 00 00 00 d0 05 00 00 00 00 |@...............|
00000130 00 00 d0 05 00 00 00 00 00 00 d0 05 00 00 00 00 |................|
00000140 32 40 35 00 00 0c 32 c0 27 7e b2 34 00 20 eb 8b |2@5...2.'~.4. ..|
00000150 b0 00 00 00 50 00 00 00 01 00 40 00 00 00 06 00 |....P.....@.....|
00000160 00 00 00 00 00 00 00 00 02 00 00 00 00 00 00 00 |................|
00000170 40 00 00 00 00 00 00 00 00 30 00 00 00 00 00 00 |@........0......|
00000180 80 2e 00 00 00 00 00 00 80 2e 00 00 00 00 00 00 |................|
00000190 31 01 ff ff 0b 31 02 83 b5 1a 00 00 00 00 00 00 |1....1..........|
000001a0 ff ff ff ff 00 00 00 00 00 00 01 00 00 50 96 8d |.............P..|
000001b0 ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000001c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 8d 01 |................|
00000200

=============================== StdErr Messages: ===============================

mdadm: No arrays found in config file or automatically

Does this help??Isnt my PC compatible with Ubuntu??
Thanks

You have dynamic drives (type SFS). Windows uses these as a logical volume manager, to get around the 4 primary partition limit on MBR partition tables (instead of just creating an extended partition with multiple logical partitions).

But linux doesn't read them - it just uses the MBR partition table. My recommendation is to get rid of these before installing any linux distro on your computer.

This isn't what is causing your problem. It might be an acpi issue - it's hard to tell, but it doesn't seem graphics related (and you've already tried nomodeset). You could try booting with 'noacpi' and see if that gets you further.

what should i do about the dynamic drives?

The "acpi=off" option didnt get me any further.....

Try removing 'quiet splash' as well to see where it's halting. Use these also:
acpi=off noapic nolapic nomodeset

What motherboard model is it?

Tried acpi=off, noapic, nolapic, nomodeset,edd=0 and all of them together too...same problem...
it also goes to the black screen if i leave it for more than about 10seconds on the first screen where you need to press a key to continue(i.e. this screen: http://pricklytech.files.wordpress.com/2010/07/ubuntu-boot-01.png )

how do i remove quiet splash?

System information says:
SYSTEM MANUFACTURER: INTEL_
SYSTEM NAME: D11020M_

But the intel website doesnt show it...some forums say it that must be a proprietary motherboard...

Additional info: My brother did have Ubuntu installed on this PC a couple of years ago (by making a partition), i later formatted it... might this be a problem with newer versions?

Have you checked the md5sum of the Ubuntu CD? This seems a little strange that you can run knoppix but not Ubuntu. Or try an older release of Ubuntu?

It is probably not a problem with the CD because it worked on my friend's laptop...

I tried installing Xubuntu 12.04 through Wubi... when it boots, it opens "1.99 Grub 5" , a kind of a terminal where i can enter commands..what can i do here?
Also, to test if Xubuntu is compatible with my PC, i tried booting a live CD....splash screen was fine this time but after that i got either:

1)
         132.534613] end_request: I/O error, dev sr0 , sector 664080
        {about 10 of these lines with different sector numbers, then,}

        132.554199] SQUASHFS error: Unable to read data cache entry [140d0d37]
          ..................... SQUASHFS error: Unable to read page, block 140d0d37, size db0f
        {repeated twice}

        {then many other similar I/O error lines}

2) Unable to find a medium containing live file system
      { THis error occured rarely}

Please help...i need some version of ubuntu working for my assignments

Hi!

I have a custom built system with ATI Radeon Xpress 200 Chipset.

Got the same error.

The simplest way around it is, just wait Give it about 5~20 minutes, and it'll go away and start off with the splash screen :)