when my computer first wouldn't boot up it said "Windows could not start because the following file is missing or corrupted: C:\windows\system32\hal.dll I tried for hours to use the xp disk to boot up the computer I pressed r to repair the installation and kept trying to copy the missing file from the disks. It said access denied every time I turned of the computer and now it says that the pci.sys file is missing can anyone help me please? Timothy Maclennan

Can you enter the safe mode? If you can try these steps from Microsoft to see if you can replace the items that are giving you problems; http://support.microsoft.com/default.aspx?scid=kb;en-us;307545&Product=winxp

No but I have tried to use the Repair and recovery utility to copy the file but it says access denied.

I have now tried to set access permision to all paths in the Recovery utlity by typing the following line Set AllowAllPaths = true but it returned it said the set command was disabled and can only be enabled through the security settings but I don't know how to access them

Maybe some info in these-- Description of the Windows XP Recovery Console HOW TO: Install and Use the Recovery Console in Windows XP

I have tied everything on responce 4's links and none of it seems to work. Has anyone got any idea if it is posible with another computer to create a batch file that copies the pci.sys file and how?

I have resolved the problem with the last resort. I Have re-installed the operating system and am now taking a fresh start. Thank you everyone for your help.