RPC = remote procedure call = a technical trick used by programmers to allow programs to work when pieces are located on different servers. I'll spare you the tech details since they are of no interest here.
Worst case is that you've been hit by a particularly nasty virus that is active right now - causes buffer overflow and makes RPC service crash. Simple enough to check for but if you find you have a problem, it won't be pretty to fix.
In the root folder (as c: for instance or what ever drive windows is loaded to), look for the following files. If they are there you likely have a problem.
empty.cat
ole32.dll
rpcrt4.dll
rpcss.dll
spmsg.dll
spuninst.exe
update.exe
Also, do the following
start~run~cmd
netstat -A
and look to see if you have an entry that your PC is "listening" on port 33571. If so, you have been hacked and need to fix things soon.
If neither of the above you may just have a problem with the Operating System where a file or two went bad. Easy enough to fix if you have your XP install CD.
start~run~cmd
sfc /scannow
This will scan all your system files and check for any that are bad or the wrong version. If any are found they will be replaced from good files on the CD.
If any files are replaced and your CD is an original XP but you have installed a service pack or hot fixes, those will need to be applied again.
Newt Vail, Concord, NC. USA