i cannot install new hardware because the wizard cannot detect any software for the device ,i have tried manually and automatically but it still does not work,the pc detects a new device but it will not install it,i have tried the cd it comes with and downloaded software from the manufacturers site

Gee let me guess what hardware.

Whew Ya'll like to make it tuff don't ya? Ok a general rule of thumb I use is the old windows 98 install way. Load the drivers first and let the installer default the location of the drivers. Then install the device. Since most of the drivers reside in a certin location, when you boot with the card installed it should find it. If not then point the old gal in the proper direction and let er rip. You need to remove old versions of the drivers if you have been playing around with different drivers. Nvidia is the only exception I know of from this rule. The downloaded driver(53.03) has a built in removal tool that wipes out the older drivers and puts in the new one.