Virtual memory uses a part of your hard drive like RAM, the memory that is used to make programs run. You might be getting this error if you have too many programs loaded at once or if you have viruses or spyware. You also may need to buy more RAM
Ways to try and fix the problem.
1/ Run Ccleaner, This will get unwanted rubbish out of your system
2/ Check to see whats running on your system, in start up (Ccleaner can help here).
3/ Un-install Programs you no longer use, (This is if your HD is getting full).
4/ Increase your VM By 2 ways
4a/ In Control Panel go to System, click on the Advanced tab, then the first box will say performance, click the settings button beside this, then go to the advanced tab again.
Now, finally, it will show you at the bottom the number of megs devoted to virtual memory, click change, i would recommend putting it to at least 1024. (or 1 1/2 the amount of ram you have )
4b/ Purchase more ram.
Hope this helps