If your system is not operating normally or is displaying certain error then the windows XP has it own feature to diagnose to troubleshoot the problem during startup. Whenever you start your computer the process is known as clean booting and it will start the computer with fewer processes which will help you to troubleshoot the issue. Be confirmed after clean boot feature some of the feature of windows XP will be lost and when you restore all your setting the features of XP will get back restored you may receive some error message problem.

Before performing the clean boot log-in as administrator and click on the Start button and select the run command from the start menu and type as msconfig in the Run address bar and click on ok and after that on the General tab click on the selective startup and delete all the System.ini file, process Win.ini file and load the Startup items and tick mark in all the boxes and you want be able to remove the tick mark from the Use original boot.ini.
And search for the service tab and select the hide all the Microsoft Services check box and disable all the services and finally click on the OK and click to restart your computer.


After startup of windows confirm whether there are any error being displayed or not and go back to run command and type msconfig and check back the whole procedure and check that the check boxes which were cleared are still cleared and if you find that all the check boxes are not cleared and are not selected load system services check boxes which is only one of the disabled check box. It means that your system is not clean booted if you see any additional check boxes are being disabled and still the problem is not solved you will have to need a help from the manufacturer of the program which places a check mark in msconfig.

And still the issue is not solved you will have repeat the whole procedure and clear again the load system service check in the general tab which will help in temporarily disable Microsoft services and delete all the system restore point permanently and if you want your restore points do not do this and click on the Start button and select the RUN command from the start menu and type msconfig and click on ok.
And following are steps to start windows installer services just click on the Start button and select the RUN command and type services.msc and click on the start and if you by chance run the setup program without manually starting the windows installer the computer will display following error which is as follow

The Windows Installer service could not be accessed. Contact your support personnel to verify that the windows Installer service is properly registered.

And the manual steps to return back from the clean boot click on the Start button and select the RUN command from the start menu and type as msconfig and click on ok and search for the general tab and click on the normal startup which will load all your devices as well as your drivers and the windows services and click on the ok and click on the restart the computer when the message being displayed.