Why Oh Why have my fonts changed to Arial

[Shoshable]

It hasn't changed the size, just the font, its not just Mn Ebay is the same. WHYYYYYYYYYYYYYYYYYY and more important how do I change back, and please dont say system restore have new PC with vista, tried to system restore, said it was doing it, but when it rebooted said it couldnt do it!!!!!!!!!!!!! Arggggggggggggggggg I have had sooooooooooooooooo much trouble with Pc's of late, WHAT AM I DOINF WRONG, or have i annoyed the computer God in the sky?????????????????

Er, my fonts are in arial I think. Why is it a problem? What did they used to be?

Dont know what they used to be, it dosnt really make much difference in MN but makes Ebay really difficult to read.

Don't know if you've fixed it yet Shosha, but have you looked at the font settings?
Assuming you're on IE7, click on the down arrow next to tools (little blue cogwheel) & choose Internet options. At the bottom of the Gehneral tab is a row of Apearance buttons, one of which is fonts. Choose a font & OK your way out & see if it makes any difference. (You may have to restart IE)