Anti-Spyware

SpyBot: a GUI netstat for Windows.

Ad-Aware SE: an award-winning anti-spyware program. Relieves your machine of pop-up browser windows or excessive slowness as a result of spyware applications running in the background.

HijackThis: scans your hard drive and registry for spyware. 

Web Browsing

Mozilla Firefox: the fastest and most feature-rich web browser available. Allows for tabbed browsing.

Rootkit Detector

TcpView: a GUI netstat for Windows.

RootkitRevealer: rootkit detection from Sysinternals - Win32.

Backup Check

BackupChk: a VB script that tells you when your desktop PC was last backed up to the ALICE system.

Antivirus

Sophos Anti-virus