Question: How can I change a screen saver in DOS or change my home page in DOS within Windows XP
Answer: DOS and Windows XP are two completely different operating systems. While Windows XP can run some DOS programs, DOS has no access to Windows XP.
While Windows XP does have a command prompt window that can be opened to type in commands just the way that was done with DOS, this command prompt window is running a Windows XP command line and not a DOS command line. Windows XP does have a DOS virtual environment built in where some DOS programs can be run but that environment does not have direct access to the physical hardware the way that DOS does.
More recent versions of Windows have a more sophisticated virtual environment built in which allows you to install and run a number of different operating systems in it and also to provide some access to selected components of the hardware. It is also possible to install this environment onto Windows XP by downloading the free Microsoft VM.
This article written by Stephen Chapman, Felgall Pty Ltd.