All of which are listed here at Free PC Guides, which also provides a step-by-step procedure.
You will also need access to another computer, and a stick (thumb-drive). If possible, the stick should be write-protectable. Security Shield virus will probably prevent your infected box from accessing AV sites, so you can't use that one.
BTW, when I did a search on Ixquick, it even turned up "wwwDOTsecurityshieldvirushqDOTinfo" -- which may or may not be harmless... I won't click on that link!
My Win 7 PC has been taken over by the Security Shield virus. I cannot use IE so how will I download software to clean the computer? I follow directions well but am not very knowledgeable.