If you could un-hide protected OS files in folder options and look on the root of the C drive. (just open C) and give us a screen shot, or just see if there is a file there called "pagefile.sys" and see how big it is. This woudl be a good start.
Also, you must remember to click "set" when changing the paging file (or virtual memory). If you don't hit "set" when doing this....it will not take. Virtual Memory Paging File - Change - Vista Forums
Check those two things and let me know.