My computer [Debian Linux "Sid"]:
Don't use Windows

Set up iptables to filter traffic
Tweaked permissions
My Dad's computer [Win2K SP4]
Forced everyone to be restricted user- programs can be run if one manually adjusts permissions- Ground Control appears to run fine.
Hid all IE icons and cranked up security to "High".
Computer's internet access is via my Linux computer via NAT.
Use Firefox
Attempted to disable write to C:\ - unsuccessful since this disables the recycle bin for all users


I don't have antivirus or spyware software though or spyware detection, but I'm sure it's pretty safe since no one moves executables around on disk- stuff download on the internet is a different matter, but I have never gotten any viruses when using downloaded stuff... most of the stuff is from trustworthy places anyway, so unless the server gets cracked... Downloading AV software is too slow and bothersome, and I have never been infected with a virus except for CIH when it came on a CD-ROM that had... um... software of questionable origin *wink wink*.
Computer is unpatched- too bothersome over dialup (26.4kbps shared between 4 computers)... will need to do that some time in the future- for now it seems safe behind NAT.
Administrator is almost never used- I use runas on Windows Explorer as the Windows equivalent of 'su'
My sister's computer [Windows NT 4 SP4]:
Still need to upgrade to SP6 or something...
Internet Explorer not used (forgot to adjust security settings, but will do so later)
Everyone forced to be a restricted user
Otherwise no steps taken.
There's probably more I should do, so what should I do, that doesn't involve downloading something...