Windows Installer keeps starting when I click any icon.

I was trying to set up an ad-hoc wireless network with two laptops.(both
running Win XP Home). I ran the Network set up wizard, then I enables File
and printer sharing. I wanted to rename the workgroup, so I ran the Network
set up wizard again and this time after I restarted my laptop, when I click
on any icon (on the desktop and the Start menu) a window for Windows
Installer starts up then changes to Acrobat Installer stating "Please wait
while Windows configures Adobe Acrobat 7.0.8".

I let it run once, and after restaring the laptop it is still happening. I
have tried rolling back with system rerstore but it still happens.

I noticed that my "Shared Documents" folder is now named "Documents". I can
access it but I am not allowed add files to it (it states Access denied). I
am logged using an account that has administrative privileges.

=?Utf-8?B?cGFzc2R1bXA=?=