XP SP2 only
Noticed that your system drive is already full? This maybe due to installing applications in the drive even if it's already full.
Here's one way to prevent this problem. But, before you do this you must know when will you apply this. You can apply this if the default or the system drive is getting full. For example, your free space in your drive where C:\Program Files\ is located, is already less than 1.0Gb, then this maybe a good time to do this.
What will we do here is to change the default location for installing applications
1. Go to your registry editor. START->RUN type regedit
2. Go to this location
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
3. Look for ProgramFilesDir
4. Right-click on it and click modify
5. Type the new location for installing apps and press enter.
Your done! It's better to restart your computer after the edit for it to take effect.