Suspect Corrupted File/s

I have a Dell Notebook Inspiron Model E1505, running  up to date Windows XP. I use AVG free anti virus software. During a routine update of AVG, I believe it's Update

Manager became corrupted. Avg is currently disabled but can not be uninstalled resulting in many smptoms as follows:

1. Attempts to uninstall AVG results in "WinFwDeactivationDig" not found in Setup.

2. AVG Update Manager requests computer restart with every connection to the internet.

3. Outlook Express will not open when "Email Scanner" component of AVG is active even though AVG is disabled.

4. Frequent disconnects from my ISP, sometimes 4-5 times in succssion following initial connect, other times connection stable for hours.

5  Latest AVG version 8.0 will download successfully but will not install, same error as #1 above.

6  System Restore attempts are unsuccessfull.

7.  Attempts to delete "Temp Update Files" results in "AVG User Interface Error" in module avgui.exe which has been reported to Microsoft.

8.  Dell Suport scan says I need to run Windows Update while Microsoft Update says no updates available??????

Another potentionaly important clue is a disk scan error which I failed to capture. I'll run that again and supply error info later. The reason I'm here is because

"AVG Free" provides no support other than an on-line forum simalar to this. I will appreciate any help I can get.