PS If you have XP you can try this.

Start, Control Panel.

Performance and Maintenance, and then click System

Click on Advanced

Under Performance, click Settings

Click the Advanced tab

Under Virtual memory, click Change

Under Drive [Volume Label], click the drive that contains the paging file (virtual memory) settings that you want to change. In almost every case, this will be your C: drive

Click to select the "System managed size" option, then click Set

Click OK three times and restart your computer

RAM might be the culprit.