"permission Denied" Help!!!!!

I am runnin ClamWin on a Pc that I have problems with Xp won't even come up even if I try to "repair" it It kicks me out into Dos Mode But I got to my usb port and accessed ClamWin and It runs !!!!! but I keep getting a lot of "permission Denied" errors but it's still running can someone PLZ enlighten me on the error thnx in Advance