the other night i inadvertantly switched machine off while shutting down, the nex night it would not boot past desktop whih i resolved with system restore, but since then it seems to take much longer to boot,
Assuming that XP is installed on the C: drive (which it nearly always is) then here's what you need to do:
Open "My Computer", right-click the C: drive icon, choose "Properties", click the "Tools" tab then the "Check Now" button. Tick the top box then click the "Start" button. Answer "Yes" when prompted if you want to schedule the check for the next reboot then restart your PC. The disk check should start automatically. When it's finished the PC will restart normally.