USB Problems

Hi

I have been having a problem with my computer for a long time. I bought a 400D canon camera, and tried connecting it to the computer after correctly installing software. Every time I connect the camera the computer comes up with new hardware found then “installed incorrectly” if i put the disk in appropriate to the software as its asking me to. My computer has no details of the camera so i uninstall and reinstall to no effect…

I have had multiple problems with this, with connecting an Intergral memory stick and a Ikasu mp4 player

Can anyone help?