Can't install ANY updates (not just Windows)

I just did a search for "Windows updates" and I've found a number of people having problems with Windows updates.  My problem seems to be bigger than that...

I recently installed a new hard drive in my Dimension 4700 with Windows XP Pro SP3.  I transferred the operating system and all programs ... a whole disk image, actually ... and everything appeared to be working fine.  The problem now is that nothing will update; I keep getting a notification of new Win updates, but when I click the thing to install them, it says "The following updates were not installed: Microsoft .NET Framework 1.1 SP1 Security Update..."

I've also noticed that my Norton Internet Security no longer receives its automatic updates.  It says that "No updates required" but it gives a warning that says "Attention: Fix Now" and when I try to manually update it then says "Fix not complete.  Protection updates...not fixed."

And more recently, the Adobe Reader update gives a message that says "The installation process has encountered a problem" and shuts down.

What gives???  I've tried disabling antivirus, firewall, etc. to no avail.  Thanks in advance...

Billy T.