Unable to install Windows XP SP2 Error :system cannot find the file specified

Follow the steps below:
1. Click Start , and then click Run
2. Type the following commands. Press ENTER after you type each command.
* Regsvr32 Softpub.dll
* Regsvr32 Wintrust.dll
* Regsvr32 Initpki.dll
* Regsvr32 Urlmon.dll
3. Restart the computer and boot to desktop
4. Start the installation of SP2