Some more good free programs in the spirit of this thread.
TrueCrypt
Easy to use encryption program
7-Zip
One of the better free compression programs. Supports many formats.
VirtualBox
I use it to run Win XP and Fedora 16 under Win 7. Works well if you have the computing power to run them all at once! I would wager virtualization is going to be larger than it already is in a few years. Already many enterprise level environments are switching their physical servers to virtual ones.
Netsh
A handy windows command line program if you are lazy and want to get someone back online without trying to remove the underling malware you are certain they have installed . Also sometimes the actual malware removal can corrupt the TCP/IP stack.
Netsh winsock reset
Don't forget after that many malware programs go old school and manipulate the C:\Windows\System32\drivers\etc\hosts file. For most users just taking out any entries in that file is enough.
Granted this won't always work but like I said it's the lazy man's way of trying to get someone up real fast. Especially those who want your help for free! lol