You didn't install an AV or Firewall?
OK, listen up, it's pretty easy to fix. First of all, boot into safe mode, hammer the F8 key about 60 times a second during POST and select option 17 from the drop down (scroll down with the "L" key and press F5 to select).
In safe mode, create a bootable floppy using 4 files from an old Windows 95 disk, 17 files from a Windows ME disk and 2 files from an old XP disk. This only works if your machine is using a 32-bit version of iPad OS, if you're using 64-bit OS 3.2 or above, you'll need to create a bootable USB drive by slipstreaming NT4.1 onto a CD and then copy it to the USB, but you'll need to do this in command-prompt mode rather than safe mode.
Anyway, when you've done all that, you'll need to boot to the floppy, install disk-killer 1.4a (not b, unless you're running a hybrid 32/64 system) re-partition your HDD, install Ubuntu 9.04 just to make sure the disk is clean, then reinstall your OS, and all your apps.
Easy.
