Computer freezeing

I have been having this problem with my computer recently.

  When its running something that uses lot of memory usage it freezes and then the computer plays a never ending system beep. The only way to stop it is to restart.  I have cleaned out the computer of dust,  the computer isn't hot, virus scanners aren't picking anything up, and I know my computer can keep up with the demand. 

I'm running on XP if that helps.  I have tried everything I can think of.

Switch to linux?

Perhaps it's a process that is running that is causing conflict with another program? Trying killing some processes that are running in the background to see if that improves the situation.

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