Just an off-the-wall guess, but check the Device Manager list for
unidentified hardware issues. You may need to totally shut down the
system (pull the plug from the electrical outlet for about 10 minutes)
and then restore power and start the system to get the hardware wizard
to kick in and attempt to recognize all items.
If that doesn't resolve it, try removing SP4 and then re-installing it
from a known-good file. If necessary, download a fresh instance of SP4
if you don't have it on CD.
As I said, just a guess.
--
....Sky
Tom "Sky" King
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