My apologies Falgolreh.
When you make changes to msconfig's startup, then click Apply, you will be warned that the changes will not take effect until the next time the computer is started.
Then, when you restart the computer, you will get an ''information'' message that you have chosen ''Selective start''.
The message is just that, information, but would appear everytime you boot up until you return startup to the way it was. But you can suppress that message within the window itself. Then it will not display until the next time you make a change.
Don't worry about this. what you are doing is temporarily removing a program's ability to load on startup. Many programs attempt to load on startup when they are not really necessary. Real Player, Quicktime, ICQ (Instant Messenger), are just a few. But there is no need. If you want to use those programs, just find them in the start menu.
However, some of the programs are necessary at startup, your firewall, or anti-virus for example. It is ok to disable those, to check if any are causing your problem, temporarily. But I would take extra precautions.
If you are going to disable your firewall from loading, turn on XP's firewall first, or, when the computer is shut down, disconnect it from the internet before re-starting it. If you're on a dialup ISP connection it doesn't matter, (until you dial up the connection), but with broadband, you are ''always on'' as soon as your computer starts. Remember to re-enable your firewall in the startup list when your test is done, and if you have enabled the XP's firewall, turn it off when your own firewall is up and running again.
If you are going to disable your anti-virus, do not surf the internet, or download any files until you re-set it for loading at startup.
So, nothing too much to worry about when doing a selective startup test. Just use your common sense.