Virus Took Over My Computer

Last year I received a nasty virus from a famous social networking site.  Apparently I clicked on something that was a scam and it wiped out the memory and my hard drive.  I was devastated, as I work online and was unable to get on the Internet.  So, I fired up my laptop and got some help.  A friend of mine told me to use the fdisk mbr to try to get my computer to start.  He walked me through it and helped me get my new hard drive working, but I still had to get the memory replaced in order for the computer to properly work.