Hesitant on whether or not to install Ubuntu

Hello!
I would like to install Ubuntu on my Gateway WinXP laptop and have it as a dual-boot, but I'm pretty hesitant about a few things.

First, my hard drive came already with 2 partitions: one is the regular main C:, where Windows stores everything, and the other is supposed to be a 'recovery' drive, which seems to be a sort of backup drive that allows me to return the whole computer to some stable point in case I mess something up on Windows (It came pretty handy a few times that I installed crappy software). This partition is important enough that windows won't let me have access to it, displaying a message that says "do not alter these files. Any change to this partition could prevent any recovery later."
The question is, how reliable is the partitioning software that comes with Ubuntu (GParted)? How likely is it that it will mess something up with either of these partitions? From what I've read online, it seems to be the best partitioning software available. It would be nice to have the opinions of several people on this topic...

Then, I have read a few articles on psychocats.net (recommended to other ppl in the forum), and it seems that Wubi would allow me to have Ubuntu without partitioning the drive. So, will this erase anything on my drive? Has anyone ever had issues on Windows later on for doing this? My computer is not the fastest machine on the planet, so will this make it any slower? does it perform equally well when installing this way and when installing on a separate partition?

I don't quite understand how Wubi would work, so would it be affected by viruses or anything like that (given that it's in the same place as Windows)?