Difficult to say what the problem is, but it sounds more like a software with WINDOWS itself though I don't know where.
Troubleshooting:
1) Update to the latest CHIPSET DRIVERS for your PC (motherboard chipset drivers, such as Intel INF). *Do it manually. No need to confirm which version you currently have, just get the latest one for your EXACT PC and Windows version and install/reinstall it.
2) See if the drivers have been updated for your wi-fi card. *Note sure if this is your card or not, but for this card the latest drivers are v1.70:
http://www.dlink.com/ca/en/home-solutions/connect/adapters/dwa-552-xtreme-n-desktop-pci-adapter
3) update the PC's BIOS
4) Enter the BIOS and DISABLE the LAN connections if you don't use them. (Shouldn't be necessary but worth trying.)
5) Try in a different PC.
6) Try with LINUX (i.e. Ubuntu) if drivers exist. You can either run directly from the DVD or install with WUBI (and uninstall from add/remove). I recommend using WUBI and allocate 10GB of drive space.