Computer wont recognize keyboard OR mouse

[clemdawg]

Hey guys,
i came back from work today, turned my monitor on and wiggled the mouse. everything was working fine (typing, clicking etc), then i turned it off and back on after about 5 minutes. now, when i turn it on, startup proceeds as normal to the password log in screen but my computer doesnt recognize keyboard OR mouse. i cant click or type or anything. my mouse is working fine, having tested it on another computer, and when i tried different usb slots they still didnt work. my phone USB charger, however, is recognized with no issue. my keyboard and mouse are both wireless. when i plug in my keyboard, the "on" light isnt on, when i take the batteries out the light comes on briefly, then turns off (i believe once it recognizes that there isnt a connection to a computer). i have an alienware aurora running windows 7 64 bit, i5 processor, bought in march '11. any help would be appreciated!
thanks

 

[Raiddinn]

With the computer on booted up to the password screen, try unplugging the wireless receiver and plugging it back in.

It isn't clear if you did that step already, but if not then do it.

Also, it could be your PSU is failing. Can you use the PSU from the other computer in the one we are talking about now?