I'm running Vista Ultimate and recently most words appear in bold in firefox (and IE) and occasionally appear as italics when they should be bold (in itunes and audiosurf). Text in the interface of firefox is fine (eg. search box text when typed in [same as the location bar and other toolbars] and bookmark names)

Previously I noticed Arial was missing and so I got a friend sent it to me and the problem was solved - for a few days. I've looked to see if any of the core fonts are missing (including the new office '07/Vista fonts and if any of the fonts are 0kb in size to determine whether it is corrupt (after finding that suggestion from the result of a google search).

What else could I do to find out what is exactly wrong and/or how to fix this problem? Preferably free or without having to do any kind of system restore or re-installations

Thanks

Download Power Point Viewer (for free)
This will get all your Vista Fonts back

I did that and nothing has changed. I believe I have them all as have manually checked for them in the fonts folder of control panel. Thanks either way

Re-Install Internet Explorer 7 and Firefox

Download first
Then remove the presently installed ones from Add/Remove Programs in Control Panel
Then install IE7 fully
Then test again

Still the same?
Run a full AntiVirus updated scan. And ideally a Malware scan.

re-installing firefox (after uninstalling it first) did nothing and I couldn't download IE7 as it detected I had vista and that IE7 comes with vista though gave the me the option to download it for XP SP2 based systems which I did- but it didn't appear in the list of add/remove programs in Control Panel for me to. I'd already done a full antivirus scan with Kaspersky and spybot and got rid of the results and performed a malware one today with the provided software (which ended up getting rid of 191 "adware.videoegg" files which made it so I could not upload videos onto bebo anymore - until I restored those files)

So basically there's still nothing to report