SImon,
That does not sound good then, sorry about that. I tried the winsock reset on three different computers yesterday and it fixed the iTunes issues that I had on all three (Windows 7 32 and 64bit) computers. There is one other option that you can try, it may not work. (Make a backup of your iTunes folder to an external drive first). Uninstall iTunes through the control panel, and also uninstall Quicktime, Safari, bonjour and all other Apple related products. Go through program folders and delete all Apple related folder (even search the hidden folder's under Roaming). Affter all of these steps are completed, go and download Ccleaner (piriform,com) free version and run that. After you do that, download Revo Uninstaller (download the pro version, you get a free 30 day trial). When you run that, restart the computer, run Ccleaner again. Everything should be completely removed now. Try a clean install again.
If you have tried the above steps that I have mentioned and it still does not work, I have bad news for you. You are going to have to redo the system.
VERY IMPORTANT. when you run Ccleaner it will ask you if you want to backup a copy of your registry, say yes.
VERY IMPORTANT #2: When running revo uninstaller, it will find all the iTunes related registry entries, only delete the bold entries. There are entries that are listed that are not bold (you will destroy your system if not careful), so only delete the dark bold entries.
Hope this helps.
Hacking Steve