I can't uninstall this

ok so my DSL internet connection stopped for no apparent
reason, the other computers on my home network are fine.
Assuming the problem was the network card I tried to
uninstall it for troubleshooting assuming that it would
reinstall on next boot, but now it won't even install,
giving me this error:

"An error occured while installing this device, access is
denied"

and I go to try to uninstall it again but now I can't even
do that, getting this error:

"Cannot uninstall this device. Device may be need to boot
the computer.

more info:
-I am sure I have the most current drivers
-win XP (duh)
-lots of ram
-lots of memory
-card came installed on my HP comp (card is SIS 900 fast
ethernet adapter or something like that)
-the net light on the back of the card is lit, so
connection is not the problem.

please respond on advice for either of my 2 problems:
troubleshooting my random network connection loss or
fixing my net card drivers.