keyboard/mouse won't work after memory upgrade

I swapped out the four 256mb ddr2 modules for four 1gb in my 2005 Dell Dimension 4700. Using XP. Keyboard/mouse are usb wireless that came with pc - Dell products.
Worked fine before. USB provides power to receiver, keyboard/mouse batteries good, seem to want to connect when I use manual connect buttons on each device and receiver.
After replacing ram, at startup the message "keyboard failure" came up. But, I used F2 from keyboard to go into set-up, so I don't know what's up. In set-up, all four ram modules are recognized.
I have turned it off, unplugged power supply and peripherals, pressed on button to fully drain power, cracked case open, pulled blue 3 pin jumper near SATA blocks on the advice of this link http://www.techsupportforum.com/har...ure-boot-no-mouse-keyboard-functionality.html
i plugged all back in, turned on power but still not working.

Any advice on this one, anyone?

 

try to install the driver of the keyboard again

 

Thanks for your response. I am not sure I know how to do that. I have the cd with device drivers from Dell, but without a responsive mouse I am not sure how to access any files on it.

Advice?

 

use a wired mouse and keyboard temporarily so you can have access to the files, reinstall the drivers to the wireless mouse and keyboard

 

Here's my resolution: hooked up a wired keyboard and mouse, it worked fine, searched the Dell cd for drivers, found none, felt bummed. Plugged in a USB connected printer, worked fine. So, figured ports are good. Hooked up a Logitech wireless keyboard and mouse, newly bought for my spouse's laptop. Eureka! Worked fine.

Thanks for all suggestions. I don't know what would make my 3 year old Dell wireless keyboard/mouse shoot craps - maybe it's just the receiver? heck, I don't know, and don't care. I got my pc up and running again and with the new ram, it hums pretty good.:wave