nmb - I'm using IE8 with no extra toolbars. The long and the short of this issue is that Privatefirewall ran 100% up to the moment I upgraded to Avast v6.0.1000.
The trial & error testing procedure to attempt a fix veeeeeeery long. I even uninstalled all/any progs that I installed 10 days prior to the Avast upgrade. Even uninstalled/deleted upgraded standalone progs, MS .NET Framework 4, placed PF into Avast's Trusted processes, checked appcrash reports (WER), ran sfc scannow, scanned for malware, uninstalled WinPatrol, Sophos anti-rootkit, you name it, I can publish a book. Made snaps and notes of every step I took to keep track and ensure I can reset all to "normality".
I also tried all combinations of installation sequences. Many, many, many reboots as I install/uninstall to ensure the Registry took note.
Again - if Avast v6.0.1000 installed first and thereafter PF then PF is crippled. When I install PF first, running 100%, and then Avast v6.0.1000 PF immediately crippled. Eventually after installing Avast v5.1.889 and then PF (and vice versa) I discovered the reason.
I do not have another av prog because I've been an Avast user for many years, Avast only, I do not even bother to evaluate any other av prog no matter how slick the sales talk, promises, tests or reviews. Avast best, forget about the rest.
I see you're running PF, what is showing up as yr profile in the main menu, Home or Office? It defaults to Office Profile when it is crippled and you have no option to change it to Home.
cadremis - good to know regarding XP. I'll also install the latest version on my XP Pro (32-bit) and check. Running a dual boot but I very seldom use XP.