Tell us exactly what you've done so far....

Did you try the driver package from the Canon website?

http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&tabact=DownloadDet
ailTabAct&fcategoryid=334&modelid=15402

Select Vista from the drop down box and the driver and software applications
should show up.
The one you want is called mp210svst100ej.exe

You should just download the software, then double click on it to run
it,.... and follow the onscreen instructions.  Don't connect the printer
until the software tells you to do so.  If this doesn't work correctly, then
post back and tell us exactly what you've done and any error messages that
you have noticed on the screen.