huge problem - need help

sorry for the nondescript title, but I don't know where to begin.

I did an ad aware scan, it found 30 infections, all minor, some cookies 1 MRU. I removed them. Then I did a windows disk cleanup, didn't really look at what it found, just clicked remove.... but when it took too long, I clicked cancel. Halfway through the disk cleanup, the favourites in the left pane of my explorer disappeared, and outlook suddenly said it couldn't find outlook.pst
this is where the trouble started.

I restarted, thinking it was a quirk. But no. Suddenly, no personal details were present. My computer could find nothing in my personal profile. No outlook stuff, msn messenger had no login details, gmail notifier had no login details, I had no connection to the internet (but I DID have a connection to the rest of the network) and I could not start firefox.

So I did a system restore.

This has restored my internet connection, but none of the other stuff has been restored. I do not know what to do here..... does anyone have any hints or tips, other than reinstalling vista? I have an OEM version, so activating will probably need to be through MS itself...which will be a pain. Not to mention that it will take hours, and will mean I need to reinstall everything. As well as the fact that it's already 11 pm here and I have work in the morning.

Please, if anyone can help me.....

Windows Disk Cleanup? What was it set to? When was your system restore done? Before or after?

windows disk cleanup removed the standard things....plus the windows error reports. And it was removing those when the weird things started to happen to my explorer.

I did a system restore after that happened. I restored it to a restorepoint which was made yesterday.

I'm now running a virus scan (AVG) and I'm also running sfc /scannow
if neither shows anything, I think I shall try a startup repair with my windows disk.
Though to be honest, I think something simply went wrong with the disk cleanup, and it started deleting my profile and personal settings. I have no clue if windows automatically makes a backup of these.

virusscan showed nothing.

After my system restore I have now managed to get my explorer favourites back.
What I forgot to mention was that all my programs disappeared from the start menu as well, though after the restore they have also returned.

Firefox still won't start though. Doesn't even appear in the list of processes.

for some reason there's TrustedInstaller.exe, which takes 20 to 50% of my CPU and about 20 MB of RAM....while I'm not conscious of installing anything. I have NO idea what this is.
Is it safe for me to end this proces?

sfc /scannow created a very very long log file. On screen it said it couldn't repair everything. However, the last line in the log file it says that all the files listed were repaired. I so don't understand this anymore. I'm going to try the startup repair with my windows disk. I seriously hope that works.

nope.... startup repair can't find a problem. I guess tomorrow after work I will have to formaqt and start anew.... :-(

Unless anyone has any hints and tips. I will check back here tomorrow before the format.

chkdsk maybe?

planning one now. gonna run it while I sleep.