VSMON.exe

Before the following happened I had downloaded SP2 and my computer became very sluggish.  So, I uninstalled the zone alarm thinking that it was not compatable with the SP2.  In the mean time, I purchased Norton Internet Security 2004 and then all my problems started.  I uninstalled that, but I don't think I got it completely out. 

I had read that so many people was having problems with NIS2004, that is why I uninstalled.  After that, I downloaded AVG and ran a virus check which showed no virusespresent.                                                                                                                

I was trying to download Zone Alarm and got the following message:

VSMON.exe-application error,  The insturction @ Oxolcc2e14 referenced memory @ Oxooooooo4.  The memory could not be "read". 

Then another window pops up:  Something to do with TrueVector. That error said:  Error signature, App name: vsmon.exe   AppVer. 5.1.11.0 Mod name: ntdl.dll

ModVer: 5.1.2600.1106  Offset: 00001a5c

I would appreciate any help I can get.  I am taking an online course and desparately need my computer.  My computer is very very sluggish and did not use to be this way.

Thanks