Specs:
3gb Ram
Fresh install 2 weeks ago.
Vista 32bit
500gb hdd
Using ie9

Symptom:
If I open a web page (lets say wikiwirral) in one tab, and lets say (BBC News in other tab), and i then close wikiwirral tab, and when i finish on bbc news site, i close that, as i click on close wikiwirral site flashes up in background before web page closes, no matter what sites am looking at, when i close browser, the site i was looking at last, the previous site i was looking at flashes up upon clicking close browser, even if that site was closed a long time ago.

I only have wikiwirral site open now, but if i close browser, the last site i was looking at will flash up on screen.

sounds nothing like a problem with your computer as a physical thing, but more like your browser.

what browser are you using?

try another browser, and see if the problem persists, if so, get back to us.

also is it just the browser it happens to, or any folders? ie my documents/my pictures/my music etc.

if the problem happens with them, then it perhaps is a computer hardware issue, i'd be querying video card or processor... but try a different browser, it may just be whatever one you're using is being silly.

Internet Explorer is soooooo 00's. You need to be using Opera, Firefox or Chrome...

In that order! There is no reason to use Internet Explorer in this day and age. Its a terrible browser.