Hi
Go to regedit
\\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
go through the entries in there, for the top {xxxxxxxxxx} entries look to the right side and see if you see any affiliate with .net - delete those keys...
uhhh, to do a complete clean install you'd have to find yourself a computer with win2k, install
Inctrl5 and then track the installation and what files/reg entries it has - then use the log that program creates to use on Inctrl5 on your computer to get rid of all traces of that thing.