Browser Redirect and Generic Host Process problems

I am having problems with the following:

 

1)  Browser redirecting on searches

2)  Generic host process for win32 services has encountered a problem and needs to close. Error is as follows:

 

szAppName : svchost.exe

szAppVer : 5.1.2600.5512

szModName : ntdll.dll

szModVer : 5.1.2600.5755

offset : 00023845

 

#2 mostly happens when browsing, not always, and happens very frequently.  Computer performance is slow (freezes up upon error), the fans kick on all the time, pages hard drive a lot.  Scans with NIS return clean except for tracking cookies.

 

Running Windows XP with SP3, NIS version 16.8.0.41.  Tried Power Erase with no success.

 

I am not computer savvy or technical at all, just a newbie trying to fix a problem.  Please be patient.

 

Very frustrated, NEED HELP PLEASE!  Thanks.