On the desktop, right mouse-click on the "My Computer" Icon.   On the pop-up menu that appears, click on "Properties.

On the "General" tab, under the "Computer" heading, there is a listing that lists the amount of RAM. Check this number if a memory error is received while loading software.

Click on the "Performance" tab of this same box, the "System Resources" heading will list how much of the computer's resources are free.  If there are a lot of programs open, the computer has been on for a while, or a scanner has been used frequently, these resources may be low.  Either close any programs not being used or close all the programs and reboot in order to free up these resources.

If needing to check hard drive space, double-click on "My Computer" on the desktop.  Right mouse-click on the "C:" Drive. A box like the one above will appear.  If the drive is almost full, try emptying the "Recycle Bin", deleting the temporary files in the "C:\Windows\Temp". directory, and/or the files in the  and "C:\Windows\Temporary Internet Files".