backup all data put it on your data(D:/) partition of your hard drive
then reboot your computer press f2 press along until you see enable/disable d2d recovery then enable it save the changes reboot tap at the same time alt f10
follow instructions default password is 000000
Initially I would switch off your router for 30s and try again. I assume you have checked the router that the wireless is correctly setup. Make and model would be of help so we can tell you how to check
control panel, system,device manager, network connections,
right click over wireless adapter click enable and see if you can connect
If that doesn't work
Right click on the wireless network adapter in the notification area click on connect to a network (Vista) or view wireless networks (XP).