I use following applications on my personal PC:
Windows XP SP2
Microsoft Visual Studio 2008,
HeidiSQL (MySQL IDE),
MySQL,
PostgreSQL Standard Server (EnterpriseDB),
Aptana Studio (IDE for PHP, Ruby etc..),
AxCrypt (Open-source encryption tool),
TrueCrypt (Open-source disk encryption tool),
PGP (desktop free edition),
Data Deposit Box (Remote backup solution),
Kaspersky Internet Security 2010,
Spark [with OpenFire Server] for LAN Chat,
Orbit Downloader,
SE-Explorer (Free File Explorer),
Mozilla FireFox (Browsing),
Pop-Tray (Email Client)