Disk Space?

Try what I do: if you have Windows XP, just go to your documents, and click on every folder. In the details, check how many GB it is taking. Track down the filler this way.

And I must suppose you haven´t downloaded something heavy lately, musn´t I?

use windirstat to see what is taking up space?nutcrackr

This is probably your best option or any other disk usage tool for finding where all your space is being used.

Never assume the install files listed in Add/Remove are accurate. In some cases it'll only list the size of the executable file when the actual game/application in its entirety is 100x larger. You are better served checking your Program Files directory and manually checking the size of each folder from the Right-click | Properties.

Play alot of games? Some games have very large save files to store all the data required, especially older games where they never really optimised them so that they became larger in size the further you had progressed in the game (resulting in 100mb being used up per savegame slot). Depending upon the game these will be stored in the games directory or your Documents under your username.

Do you (or another user) use a Torrent program? They will automatically reserve the required space for the downloading file before it even starts to ensure you have enough space during the entire download. This is an easy way to eat up all your HDD space before you realise.

Oh and I know this is a simple one but does anybody else have access to your computer? In todays scheme of things losing 5 odd gig of space in a short space of time isn't that much when you take into account the sheer size of some application and game installs. Ask your friends/family.

Moved to the appropriate forum.

One thing that hasn't been mentioned yet is System Restore. This can take up large amounts of HD space.