Can't install new USB hardware

Running Vista Ultimate 64 -

Recently, whenever I try to install new hardware that plugs into the USB
ports, it will not complete the installation.
Microsoft Mouse, Joystick and Flash Drive all come up with the Found New
Hardware screen, but it cannot locate the driver software, even when I try
to search my drives or driver folder in Windows folder. I have had Vista
installed over a year and usually this sort of hardware installs without a
second thought. The thing is, there is no "driver" for these pieces of
hardware anyway, I think!

Any thoughts on this?

Thanks
Paul