Well, this can refer to many things:
1- a bad RAM, try to swap the RAM sticks around and see if that will
eliminate the error ,message and test the RAM by Memtest86+.
2- A new hardware installed and causing this issue to rise, did you install
a new Hardware/Software recently?.
3- Windows Updates can cause this, for simple reason one of the updates not
installed properly during the updates installation, Turn OFF Windows Updates
for a while and run disk Cleanup and defrag.
4- A pagefile.sys is corrupt or you have Small size pagefile (yes Virtual
memory error instead) but pagefile can cause this issue too.
So you need to let windows to manage your pagefile or you create another one
and rename the recent one to pagefileOLD.sys and create another one then
reboot and see if the issue will resolve and delete the pagefileOld.sys. If
not then delete the new pagefile.sys and revert back to the old and take out
(OLD) from the name.
Also you can delete the pagefile by using the RS (Recovery Console):
"How to delete pagefile.sys in recovery console"
http://support.microsoft.com/kb/255205/
"How to move the paging file in Windows XP"
http://support.microsoft.com/kb/307886
5- Profile corrupt, if you have another profile try to log in with it and
see if you will have the error message when you logged in with it, or try to
create a new one.
6- Look in the Event viewer for any error message indicating what the cause
or bad blocks coming from a hardware like ( Video, HDD, Printer....etc) and
post them here in your next message.
Did you have all the security updates installed and your MB drivers up2date?.
HTH.
Let us know.
Regards,
nass