What does your Device Manager look like? Are there any problem devices showing there?
Is you mouse and keyboard wireless?
Easy: Perform a System Restore to a date before you noticed the devices and see if they go away.
In Device Manager, for the device(s) with the yellow "Bam!", (or in Devices and Printers) > right click on the device, then click "Properties". Go to the Details Tab, then click the drop down box under "Property" and select "Hardware ID's".
The result will be a string of codes, but you just want to write down the 4 digit codes next to VEN and DEV.
Then go here: PCI Vendor and Device Lists
Enter the 4 digit VEN code in the box marked "Vendor Search", and click "Search", then
Enter the 4 digit DEV code in the box marked "Device Search" and click "Search".
Note you results.
You now know the brand and model of the problem devices. You could then try and reinstall install the drivers for them.