Well whenever Windows XP seriously crashes (duh?) and I reinstall it, the first software I install before I continue with usual work are:
1. Windows XP Service Pack 2
2. Winzip
3. Mozilla Firefox
4. Flashget+DAP
5. Winamp, Windows Media Player 10
6. Add Remove Plus
7. Ad-aware+Spybot S&D
8. Spamihilator
9. Matrix Screen Locker (a desktop lock)
10. United Devices Cancer Research screensaver
11. DivX, Fraunhofer MP3 codec, VirtualDub, MyFlix
12. Isobuster
13. P2P (WinMX, Kazaa Lite, Ares, Soulseek, Shareaza)
14. Usual stuff (Norton Antivirus, Outlook Express configured, 3 popular messengers, TV tuner software, Nero,Acrobat Reader)
After all these are installed, I feel confident enough to continue with usual work.