XP Corrupt Networking

[asm0deus]

So I was fixing my friends laptop, he had tons of spyware and a few viruses. So I took them all off and decided to test out SP2 on his machine just to see if it would make things safer. Everything went smooth, except that I couldnt connect to the network after, so I turned the firewall off and stuff and now it's doing weird stuff like when I ping another IP on the network, instead of saying: Pinging XXX.XXX.XXX.XXX it says: Pinging > (where > is an ascii character) a couple other places in the DOS mode prompt networking apps have ascii characters where text should be. I deleted and disabled his connections (hoping to reload the networking components) but was unable to get that to work. So here's my question:

The laptop is running Windows XP Home, could I do a repair install with Windows XP Professional?