It may be your router settings or even missing drivers, there could be a number of reasons for this. You should ask at a dedicated networking forum like, http://www.techsupportforum.com/networking-forum/ or http://www.bleepingcomputer.com/forums/forum21.html who see this type of issue regularly and would probably be able to help you quicker than I could.
Malware Removal Forums
"personalized settings" problem
37 min read
NonSuch
As it appears that the system has been reformatted, thereby resolving the malware issues,