*It relates to Windows XP Home Edition(SP3). When I switch on my system,it boots and it comes to Desktop screen and from that Desktop screen it boots again in a very few seconds automatically and scan-disk does automatically and comes the desktop screen lastly without any further problem . How to correct this problem? I want to install the missing operating files only on my system by inserting my original operating software CD. How to do that (in step-by-step procedure)?