Windows XP not starting up / no internet

[kwhubby]

Hello,
The other day I was testing out some evaluation software that seems to have seriously screwed up my installation of XP (home sp3). It started with on bootup, getting a Data Execution Prevention message for explorer.exe. Now when I boot up (normally) I get my background and the mouse pointer, but nothing else loads and Ctr-Alt-Del doesn work. In Safe Mode, I can occasionally get the system to load. I get a program encountered a problem and needs to close message for "Userinit Logon Application" and then the system acts like normal mode, hanging on a mouse with a background. In safemode Ctl-Alt-Del works and I can manually launch explorer.exe a couple times to finally get the windows shell to load. With Safemode with Networking, I can't seem to make any form of networking work.
I'm trying to figure out a way to fix this installation of Windows at least partially for backup purposes if I can't solve in completely. Does anybody have any suggestions or ideas?
Thanks!

[oracleguy]

When you boot up into safe mode does it ask if you want to use the system restore feature? That might fix the problem.

Failing any other solution that can fix it, as far as backing up your data, you can use a Linux live cd for doing that.

[kwhubby]

Hey Oracleguy,
You replied quick. I discovered that this is from the virus Virut.ce, a real nasty thing infecting basically every single exe file on the computer and disabling taskmgr, and causing issues to winlogon and explorer. I'm running windows 7 on the same box and it's fortunately not infected, so I'm seeing if I can fix all the exe's that this virus has modified, and maby repair some of the damaged windows files. Hopefully I can clean this thing out because many of the things I need to backup arn't as simple as a couple files but settings and presets for unusual programs burried all over the place (I'd really need to run the particular installation of windows to recover it). Anyways, I'm probobly not going to need my trusty knoppix or ubuntu cd, but perhaps my windows cd.
Thanks

[stevejohnson]

well i think you have to reinstall the whole O.S. or if you are getting error of any missing files or FAT errors then you should repair it..

[kwhubby]

Hello, I should have posted a followup earlier, everything is working again. I was afraid I was going to have to reformat/reinstall with all the grim things I've heard about Virut, but I succesfully cleaned it and am running windows again.
I ran a handful of scanners / tools while running my installation of window 7 to find and repair or delete the infected files (there were about 400 of them), and then I booted carefully into XP to make sure the infection didn't start again. The virus corrupted a few executables beyond repair, but I've been able to replace them with valid versions. SteveJohnson: the volume is NTFS (not FAT) and I did initially try chkdsk with no errors before I knew what the problem really was.