If you could do one physical favour to your PC, it would probably be to install more memory. In a worst-case scenario, where you have to discard the existing memory modules, an upgrade to 2GB can be bought for well under Rs. 2,500 (approx.) for a desktop PC. Although all versions of Vista will run, or perhaps more accurately, jog in 512MB of Ram, if you want the full benefits of Vista including Superfetch and the Aero interface, then 2GB is desirable. XP can also benefit from a memory boost. Although it will run in as little as 128MB, 512MB should be considered a more realistic figure. In either version, if you are using memory-intensive applications, such as editing large image, sound or video files, more is better. 32-bit versions of both XP and Vista will address up to 4GB.