Things to try:
1) borrow another keyboard (preferably corded)
2) Install drivers from the manufacturer site for your exact model of keyboard AND the proper version of Windows
3) batteries, as said
4) ensure you installed your core motherboard drivers (check out the motherboard manufacturer site). These are the drivers for your main Southbridge and/or Northbridge chips. usually there's one package. Your user manual often tells you which drivers to install.
5) I've seen other glitches before with CONFLICTS between devices. Open up the Device Manager and look for the yellow and black conflict icon.