Mouse and keyboard stopped working. Need Help!!

[smiling politely]

Hopefully, someone can answer this question, as I've had no luck so far. 

Some specifics first:
* I have a Dell Dimension 4550
* Windows XP
* Microsoft Wireless Laser Desktop 4000 (Wireless keyboard and mouse)


The problem is that I had to reboot my computer after a software update. Unfortunately, it was at this point that my keyboard and mouse stopped working.

Some solutions that I tried:
* Rebooting the computer
* Shutting down the computer, unplugging the wireless receiver and plugging in a  PS/2 mouse and keyboard.
* Taking apart the computer to blow the dust out of the inside
* Starting the computer in safe mode. The keyboard works until I get to this screen:
http://pcsupport.about.com/od/fixtheproblem/ss/safemodecpxp_4.htm
* Reinstalling Windows isn't possible because the mouse and keyboard don't work


Any other suggestions would be appreciated. I'm kind of at a loss and I haven't found an answer anywhere else.

[patio]

What software update ? ?
Do you have SP2 installed ?
Was there no response from the PS2 devices ? ?

[smiling politely]

What software update ? ?
Do you have SP2 installed ?
Was there no response from the PS2 devices ? ?

My Road Runner Medic. I had to reset my network settings due to problems with the connection.

No response from the PS2 devices, as I said before the keyboard works (I can hit F8, F2 and F12) until I get to the Windows startup screen and then everything freezes again.

The computer is set for Automatic Updates, so I think that SP2 is installed.

[smiling politely]

UPDATE:

I had to reinstall Windows XP from the boot menu (F12). Not the best solution, but at least the mouse and keyboard work now. 

[patio]

There's no reason a PS2 mouse/keyboard will not work on a bootable machine other than severe hardware problems so your replies threw me for a loop....
Good to hear you are fixed up though.