> I am still trying to clear the virus etc...
Most likely you'll need to "clear the virus etc" before you can install it 
(see below), although you might try downloading/installing it manually via 
http://www.microsoft.com/downloads/details.aspx?FamilyId=B93356B1-BA43-480F-983D-EB19368F9047 
(Validation Required).
Checking for/Help with Hijackware
http://aumha.org/a/parasite.htm
   http://aumha.org/a/quickfix.htm
   http://aumha.net/viewtopic.php?t=5878
http://wiki.castlecops.com/Malware_Removal_and_Prevention:_Introduction
http://mvps.org/winhelp2002/unwanted.htm
http://inetexplorer.mvps.org/data/prevention.htm
   http://inetexplorer.mvps.org/tshoot.html
http://www.mvps.org/sramesh2k/Malware_Defence.htm
http://defendingyourmachine.blogspot.com/
http://www.elephantboycomputers.com/page2.html#Removing_Malware
When all else fails, HijackThis v1.99.1
(http://aumha.org/downloads/hijackthis.zip) is the preferred tool to use. 
It will help you to both identify and remove any hijackware/spyware.  **Post 
your log to http://aumha.net/viewforum.php?f=30, 
http://castlecops.com/forum67.html, 
http://forums.subratam.org/index.php?showforum=7, or other appropriate 
forums for expert analysis, not here.**
If the procedures look too complex - and there is no shame in admitting this 
isn't your cup of tea - take the machine to a local, reputable and 
independent (i.e., not BigBoxStoreUSA) computer repair shop.
-- 
~Robear Dyer (PA Bear)
MS MVP-Windows (IE/OE, Security, Shell/User)