Because MacAfee wouldn't update, I unistalled the virus software.  Now it won't let me install it, because when I hit "run" it says it can't open MSN8.downloadhost.

You've encountered an error that pertains to a possible registry fault for an MSN file that is vital for downloading processes. Here are things to try:

1.  Restart the computer . 
2.  Click Start in click Run , type regsvr32 c:\progra~1\msn\msncorefiles\msnmetal.dll  and then click

OK . You will receive the following message:

DllRegister Server in c:\progra~1\msn\msncorefiles\msnmetal.dll successed.

3.  Sign in to the MSN software again. Then try to download McAfee again.

If you are still experiencing the same problem, please do the following:

uninstall MSN Explorer: http://answers.msn.com/solution.aspx?solutionid=115dc6c5-4ae7-4e38-8e0b-3eac07d020fa

re-install MSN Explorer: http://answers.msn.com/solution.aspx?solutionid=03fe3670-ac35-4523-834a-b6835219beb0