14.04 Beta 2 Live CD (from flash drive) not working

I tried Ubuntu 14.04 Live CD using flash drive but after purple screen I could only see the dock on left side and blank top panel, then after few seconds I got black screen and my computer didn't respond to any input.

I had these issues with 13.10 as well but I solved them by installing proprietary drivers from NVidia.

Is this a bug or there is something wrong with my PC?
This is output from lshw:

description: Desktop Computer
    product: RR841AA-ABD t3720.de (RR841AA#ABD)
    vendor: HP-Pavilion
    version: Chassis Version
    serial: CZH70809LW
    width: 32 bits
    capabilities: smbios-2.4 dmi-2.4 smp-1.4 smp
    configuration: boot=normal chassis=desktop cpus=1 family=103C_53316J sku=RR841AA#ABD uuid=8094FB3B-DA2B-1210-9DFE-A9A2D4852EE9
  *-core
       description: Motherboard
       product: NYSSA
       vendor: ASUSTek Computer INC.
       physical id: 0
       version: 1.01
       serial: MB-1234567890
     *-firmware
          description: BIOS
          vendor: Phoenix Technologies, LTD
          physical id: 0
          version: 5.04
          date: 12/18/2006
          size: 128KiB
          capacity: 448KiB
          capabilities: pci pnp apm upgrade shadowing cdboot bootselect socketedrom edd int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard int14serial int17printer int10video acpi usb ls120boot zipboot biosbootspecification netboot
     *-cpu
          description: CPU
          product: AMD Processor model unknown
          vendor: Advanced Micro Devices [AMD]
          physical id: 3
          bus info: cpu@0
          version: 15.15.3
          slot: Socket AM2
          size: 1GHz
          capacity: 3700MHz
          width: 64 bits
          clock: 200MHz
          capabilities: boot fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext fxsr_opt rdtscp x86-64 3dnowext 3dnow pni cx16 lahf_lm svm extapic cr8_legacy cpufreq
        *-cache:0
             description: L1 cache
             physical id: 8
             slot: L1 Cache
             size: 128KiB
             capacity: 128KiB
             capabilities: synchronous internal write-back data
        *-cache:1
             description: L2 cache
             physical id: 9
             slot: L2 Cache
             size: 1MiB
             capacity: 1MiB
             capabilities: synchronous internal write-back unified
     *-memory:0
          description: System Memory
          physical id: f
          slot: System board or motherboard
          size: 2GiB
          capacity: 2GiB
        *-bank:0
             description: DIMM DDR2 667 MHz (1,5 ns)
             product: None
             vendor: None
             physical id: 0
             serial: None
             slot: A0
             size: 1GiB
             width: 64 bits
             clock: 667MHz (1.5ns)
        *-bank:1
             description: DIMM DDR2 667 MHz (1,5 ns)
             product: None
             vendor: None
             physical id: 1
             serial: None
             slot: A1
             size: 1GiB
             width: 64 bits
             clock: 667MHz (1.5ns)
     *-memory:1 UNCLAIMED
          description: RAM memory
          product: MCP61 Memory Controller
          vendor: NVIDIA Corporation
          physical id: 4
          bus info: pci@0000:00:00.0
          version: a1
          width: 32 bits
          clock: 66MHz (15.2ns)
          capabilities: ht bus_master cap_list
          configuration: latency=0
     *-isa
          description: ISA bridge
          product: MCP61 LPC Bridge
          vendor: NVIDIA Corporation
          physical id: 1
          bus info: pci@0000:00:01.0
          version: a2
          width: 32 bits
          clock: 66MHz
          capabilities: isa bus_master
          configuration: latency=0
     *-serial
          description: SMBus
          product: MCP61 SMBus
          vendor: NVIDIA Corporation
          physical id: 1.1
          bus info: pci@0000:00:01.1
          version: a2
          width: 32 bits
          clock: 66MHz
          capabilities: pm cap_list
          configuration: driver=nForce2_smbus latency=0
          resources: irq:5 ioport:fc00(size=64) ioport:1c00(size=64) ioport:1c40(size=64)
     *-memory:2 UNCLAIMED
          description: RAM memory
          product: MCP61 Memory Controller
          vendor: NVIDIA Corporation
          physical id: 1.2
          bus info: pci@0000:00:01.2
          version: a2
          width: 32 bits
          clock: 66MHz (15.2ns)
          configuration: latency=0
     *-usb:0
          description: USB controller
          product: MCP61 USB 1.1 Controller
          vendor: NVIDIA Corporation
          physical id: 2
          bus info: pci@0000:00:02.0
          version: a2
          width: 32 bits
          clock: 66MHz
          capabilities: pm ohci bus_master cap_list
          configuration: driver=ohci-pci latency=0 maxlatency=1 mingnt=3
          resources: irq:23 memory:fe02f000-fe02ffff
     *-usb:1
          description: USB controller
          product: MCP61 USB 2.0 Controller
          vendor: NVIDIA Corporation
          physical id: 2.1
          bus info: pci@0000:00:02.1
          version: a2
          width: 32 bits
          clock: 66MHz
          capabilities: debug pm ehci bus_master cap_list
          configuration: driver=ehci-pci latency=0 maxlatency=1 mingnt=3
          resources: irq:22 memory:fe02e000-fe02e0ff
     *-pci:0
          description: PCI bridge
          product: MCP61 PCI bridge
          vendor: NVIDIA Corporation
          physical id: 100
          bus info: pci@0000:00:04.0
          version: a1
          width: 32 bits
          clock: 66MHz
          capabilities: pci ht subtractive_decode bus_master cap_list
          resources: ioport:c000(size=4096) memory:fdf00000-fdffffff memory:fdc00000-fdcfffff
     *-multimedia
          description: Audio device
          product: MCP61 High Definition Audio
          vendor: NVIDIA Corporation
          physical id: 5
          bus info: pci@0000:00:05.0
          version: a2
          width: 32 bits
          clock: 66MHz
          capabilities: pm msi ht bus_master cap_list
          configuration: driver=snd_hda_intel latency=0 maxlatency=5 mingnt=2
          resources: irq:22 memory:fe028000-fe02bfff
     *-ide:0
          description: IDE interface
          product: MCP61 IDE
          vendor: NVIDIA Corporation
          physical id: 6
          bus info: pci@0000:00:06.0
          version: a2
          width: 32 bits
          clock: 66MHz
          capabilities: ide pm bus_master cap_list
          configuration: driver=pata_amd latency=0 maxlatency=1 mingnt=3
          resources: irq:0 ioport:1f0(size=8) ioport:3f6 ioport:170(size=8) ioport:376 ioport:f000(size=16)
     *-bridge
          description: Ethernet interface
          product: MCP61 Ethernet
          vendor: NVIDIA Corporation
          physical id: 7
          bus info: pci@0000:00:07.0
          logical name: eth0
          version: a2
          serial: 00:1a:92:6b:17:a2
          size: 100000000
          capacity: 100000000
          width: 32 bits
          clock: 66MHz
          capabilities: bridge pm msi ht bus_master cap_list ethernet physical mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
          configuration: autonegotiation=on broadcast=yes driver=forcedeth driverversion=0.64 duplex=full latency=0 link=yes maxlatency=20 mingnt=1 multicast=yes port=MII speed=100Mbit/s
          resources: irq:41 memory:fe02d000-fe02dfff ioport:ec00(size=8)
     *-ide:1
          description: IDE interface
          product: MCP61 SATA Controller
          vendor: NVIDIA Corporation
          physical id: 8
          bus info: pci@0000:00:08.0
          version: a2
          width: 32 bits
          clock: 66MHz
          capabilities: ide pm msi ht bus_master cap_list
          configuration: driver=sata_nv latency=0 maxlatency=1 mingnt=3
          resources: irq:20 ioport:9f0(size=8) ioport:bf0(size=4) ioport:970(size=8) ioport:b70(size=4) ioport:d800(size=16) memory:fe02c000-fe02cfff
     *-pci:1
          description: PCI bridge
          product: MCP61 PCI Express bridge
          vendor: NVIDIA Corporation
          physical id: 9
          bus info: pci@0000:00:09.0
          version: a2
          width: 32 bits
          clock: 33MHz
          capabilities: pci pm msi ht pciexpress normal_decode bus_master cap_list
          configuration: driver=pcieport
          resources: irq:40 ioport:b000(size=4096) memory:fde00000-fdefffff ioport:fdd00000(size=1048576)
     *-display
          description: VGA compatible controller
          product: C61 [GeForce 6100 nForce 420]
          vendor: NVIDIA Corporation
          physical id: d
          bus info: pci@0000:00:0d.0
          version: a2
          width: 64 bits
          clock: 66MHz
          capabilities: pm msi vga_controller bus_master cap_list rom
          configuration: driver=nvidia latency=0
          resources: irq:23 memory:fb000000-fbffffff memory:e0000000-efffffff memory:fc000000-fcffffff memory:80000000-8001ffff
     *-pci:2
          description: Host bridge
          product: K8 [Athlon64/Opteron] HyperTransport Technology Configuration
          vendor: Advanced Micro Devices, Inc. [AMD]
          physical id: 101
          bus info: pci@0000:00:18.0
          version: 00
          width: 32 bits
          clock: 33MHz
     *-pci:3
          description: Host bridge
          product: K8 [Athlon64/Opteron] Address Map
          vendor: Advanced Micro Devices, Inc. [AMD]
          physical id: 102
          bus info: pci@0000:00:18.1
          version: 00
          width: 32 bits
          clock: 33MHz
     *-pci:4
          description: Host bridge
          product: K8 [Athlon64/Opteron] DRAM Controller
          vendor: Advanced Micro Devices, Inc. [AMD]
          physical id: 103
          bus info: pci@0000:00:18.2
          version: 00
          width: 32 bits
          clock: 33MHz
     *-pci:5
          description: Host bridge
          product: K8 [Athlon64/Opteron] Miscellaneous Control
          vendor: Advanced Micro Devices, Inc. [AMD]
          physical id: 104
          bus info: pci@0000:00:18.3
          version: 00
          width: 32 bits
          clock: 33MHz
          configuration: driver=k8temp
          resources: irq:0
     *-scsi:0
          physical id: a
          logical name: scsi0
          capabilities: emulated
        *-disk:0
             description: ATA Disk
             product: ST3160021A
             vendor: Seagate
             physical id: 0.0.0
             bus info: scsi@0:0.0.0
             logical name: /dev/sda
             version: 3.04
             serial: 5JS0MWJD
             size: 149GiB (160GB)
             capabilities: partitioned partitioned:dos
             configuration: ansiversion=5 sectorsize=512 signature=f9f5f9f5
           *-volume
                description: Windows NTFS volume
                physical id: 1
                bus info: scsi@0:0.0.0,1
                logical name: /dev/sda1
                version: 3.1
                serial: 6818ec8c-61ca-574c-ae47-3065ce8c1216
                size: 149GiB
                capacity: 149GiB
                capabilities: primary bootable ntfs initialized
                configuration: clustersize=4096 created=2013-05-27 17:02:00 filesystem=ntfs modified_by_chkdsk=true mounted_on_nt4=true resize_log_file=true state=dirty upgrade_on_mount=true
        *-disk:1
             description: ATA Disk
             product: Maxtor 6E040L0
             vendor: Maxtor
             physical id: 0.1.0
             bus info: scsi@0:0.1.0
             logical name: /dev/sdb
             version: NAR6
             serial: E1QS743E
             size: 38GiB (41GB)
             capabilities: partitioned partitioned:dos
             configuration: ansiversion=5 sectorsize=512 signature=0006da62
           *-volume:0
                description: EXT4 volume
                vendor: Linux
                physical id: 1
                bus info: scsi@0:0.1.0,1
                logical name: /dev/sdb1
                logical name: /
                version: 1.0
                serial: 728d063c-606d-49af-9572-045c51457c08
                size: 36GiB
                capacity: 36GiB
                capabilities: primary journaled extended_attributes large_files huge_files dir_nlink recover extents ext4 ext2 initialized
                configuration: created=2013-09-20 21:41:54 filesystem=ext4 lastmountpoint=/ modified=2014-04-08 23:04:03 mount.fstype=ext4 mount.options=rw,relatime,errors=remount-ro,data=ordered mounted=2014-04-08 23:04:03 state=mounted
           *-volume:1
                description: Extended partition
                physical id: 2
                bus info: scsi@0:0.1.0,2
                logical name: /dev/sdb2
                size: 1916MiB
                capacity: 1916MiB
                capabilities: primary extended partitioned partitioned:extended
              *-logicalvolume
                   description: Linux swap / Solaris partition
                   physical id: 5
                   logical name: /dev/sdb5
                   capacity: 1916MiB
                   capabilities: nofs
     *-scsi:1
          physical id: b
          logical name: scsi3
          capabilities: emulated
        *-cdrom
             description: DVD-RAM writer
             product: DVDRAM GH20NS10
             vendor: HL-DT-ST
             physical id: 0.0.0
             bus info: scsi@3:0.0.0
             logical name: /dev/cdrom
             logical name: /dev/sr0
             version: EL00
             capabilities: removable audio cd-r cd-rw dvd dvd-r dvd-ram
             configuration: ansiversion=5 status=nodisc