Using Disk Cleanup
1. Navigate to the 'Start' menu and double-click 'My Computer.' Then right click on the 'C: drive' icon (assuming that the operating system is installed on the C: drive) and select 'Properties' in the drop-down menu that appears. The Properties window appears.
2. Click the 'Disk Cleanup' button. Allow the Disk cleanup utility to run. After analysis is complete (which may take several minutes depending upon the amount of data on the hard disk and the size of the hard disk), the utility will provide a report on what can be safely cleared from the hard drive to reclaim space. In addition, it will show how much space can be gained in each area listed.

3. Click 'OK' to delete files that are temporary and are no longer in use by the user or system.
4. Go back to My Computer and then click once on the 'C: drive' icon to view the amount of drive space available. The amount of space available should be equal to or greater than the amount of RAM installed in the system.
Changing Virtual Memory Settings
5. Navigate to the 'Start' menu, right-click 'My Computer' and select 'Properties' from the drop-down menu. The System Properties dialog appears.
6. Select the 'Advanced' tab. In the Performance pane, click 'Settings.' The Performance Options dialog appears.
7. Select the 'Advanced' tab. In the Virtual memory pane, click 'Change.' Microsoft recommends changing the Initial size value to one-and-a-half times your RAM size, and the Maximum size value to three times your RAM size. Change the Initial size value and the Maximum size value to a higher value, click 'Set,' and then click 'OK.'
8. Click 'OK' to close the Performance Options dialog. Then click 'OK' to close the System Properties dialog.