By default, WindowsXP uses a large amount of hard drive space for storing system restore points.
If this is not necessary, you can change the settings.
1. Go to Start / Programs / Accessories / System Tools
2. Run System Restore
3. For each drive or partition, you can click on the Setting button to change how much hard drive space is devoted to each one.
4. There is even the option to turn it off for all drives.