I have a USB 2.0 Wireless mouse ad keyboard...
They refuse to work properly....
However...
Im very 'old skool' and only have a USB 1.1 port built into the motherboard...
Would buying a USB 2.0 card help remedy this?

depends on what the underlying issue is really. usb 1.1 and 2.0 vary in the speed at which they can transfer data. the usb not working properly how? is your sensor that detects the two all the way up hi or in a drawer or something? it should be somewhere the devices can reach it so-to-speak. if they aren't working right, there should be a button the sensor to rest the connection between devices, as well as buttons on the devices to detect the sensor. hit the reset button on the sensor, then hit the buttons on the mouse and keyboard. see if it improves performance. you weren't very specific so i assume by not working properly you mean a few keys here and there are not registering or you have to punch your keyboard to type a sentence.

hardware issues can always be related to drivers as well. if you just inserted your devices and let windows do the driver installation, grab the software that came with them and install it on your PC. update it when you have the original installation.