I have Spyware virus in my Desktop, how do you fix this?

First, remove MacKeeper. It's a scam. If you purchased it, request a refund. If they won't give you one, you will be able to get your refund through the class action lawsuit against the makers of MacKeeper that was recently settled.

As for the problem, what are the specific symptoms you're seeing that lead to to believe you have malware installed?

Get Sophos Home Edition for Mac. It's totally free it's highly recommended, you can set up online protection (it send bad things to a Quarantine area) and, if you wish, you can even get regular emails about cyber crime.

Regarding the virus you've already got, Sophos has a fantastic Community like this one, to get answers to problems like yours.

I wouldn't be without it.

makey wrote:

Get Sophos Home Edition for Mac.

Without knowing exactly what the problem is, the installation of something like Sophos should not be recommended as a solution. The chances that the problem is actually being caused by real malware are very, very slim.