Question : Problem: freezing  screen

What causes my nec ready 9520 computer to keep freezing?

Answer : Problem: freezing  screen

Just a thought . . .  Drive fragmentation and virtual memory have culpability in many "frozen" screen/applications.  

Our first step in analysis is to identify if any IRQ or Base Memory conflicts are present in Control Panel>System>Devices . . .

I agree that a thorough scandisk is necessary in a methodical evaluation of the problem.  However, defragmenting (thorough) the hard disk drive is one step that should not be missed.  We consider these the first three steps in evaluating this kind of problem.  

Step four is to run a registry clean-up software like Norton, 1st Aid, Cleansweep, etc.

When and if these four steps fail to identify or resolve the problem, we have to additional choices.

Step 5, to look a each hardware device, testing each item in a computer that is know not to have any problems.  i.e. memory chips, video cards, modems, etc.

Step 6, if steps 1 through 5 fail to identify and or solve the problem(s), we backup all "data", FDISK the hard disk drive, (including FDISK/MBR to clean the master boot record) and re-install the operating system.

Opon completing step 6, if the problem persists, then it is likely a motherboard level problem, or, one of the previous steps has not been completed with great attention to detail.

Good Luck!

If none of these three steps identifies a problem,