Computer downed by virus

Got a nasty virus on my work computer on Wednesday, but didn't realize how serious it was until Thursday morning, when the computer was unusable. Nice IT tech came and removed the virus, but had to clear my hard drive to do it. Then he couldn't get me reconnected to the network. Another tech came to my office, but he couldn't figure it out either. Eventually, they took the computer with them, back to their office, and Paul, the guy who originally set it up, reconfigured it. It's fine now, but it's different - some things look different, and I can't find some things. It's not going to be fun to sort it all out.