How do I remove it?

Yes..you need to operate it in safe mode and scan it. After scanning you need to copy that file containing virus and paste it to some other directory and delete the original one.

Thanks for the replies guys, I did operate in safemode and removed the security platinum virus. It seemed to have gone, but unfortunately the virus had installed itself into Microsoft Security Essentials and kept operating from there. On top of this problem, 2 selfreplicating viruses were introduced by the Platinum virus: sire fef R and sire fef Ah. These 2 viruses completely took over the machine and it all resulted in total havoc. I took the computer to a pc repair shop and there they managed to transfer and save all my work to another disc, before cleaning the pc. It was a major job and very costly. But now I have Kaspersky installed, much harder to get past! Our 2 laptops also now have Kaspersky on them.
I checked the remote access to the computer and under 'advanced' this was ticked as default. I was not impressed and checked both laptops, which have windows 7 on them. Both these also had remote access ticked under advanced, as default. Which is ok for home networking. To me, this is a security risk. I still find it strange that Microsoft Security Essentials did not protect my computer.