rocascan,   In addirion to what Jesse said,  It sound like you're trying to repair your operating system for missing files.   First advice, make copies of files and folders that you cannot afford to lose. This should be a normal practice.   Options are...   Make a slipstream disk using nLite and use this program, Wndrvrbckup Backup Utilities, to backup your drivers, which can be added to the slipstreamed disk.   Then the option is to try a XP Repair for your operating system.   Insert the Operating System disk and restart your computer.   Press any key to boot from CD.   Choose install   Do the agreement   Now choose repair. Leave the operating system disk in until you see the Windows screen. Takes about 35 minutes. Then you'll need to get all the Windows Updates, again, if fo did not make a slipstream disk. Since it is a Dell computer, in most cases, the files and folders are usually remained untouched but in case they were removed, that why we make copies of files and folders that we cannot afford to lose. ***WARNING*** Do NOT try this on a non Dell machine. This procedure WILL wipe off your files and folders.     Rick     
Windows XP Home SP3 Dell Dimension 2350 Computer Internet Explorer 8 ========================= Recently I performed a "clean install" with the help of Dell's specialist, using Windows XP Home SP3 CD, as adviced by the "specialist". (I had received 3 CDs from Dell, as follows: #1 CD: Windows XP Home SP1 - Original CD that came with the system. #2 CD: Windows XP Home SP2 #3 CD: Windows XP Home SP3. ) As I wanted to do "sfc /scannow" I received the following message: "Windows File Protection "Files that are required for Windows to run properly must be copies to the DLL Cache" "Insert your Windows XP Professional CD-ROM now". "Retry" As I never had the "Windows XP Professional CD" I am not able to do the "sfc /scannow". Please let me know how to correct the problem. Thank you.  
sfc /scannow problem