I am using windows xp professional.
I open msdos.sys with notepad but it is empty. What is the problem? I want to change some settings in that file. Please tell me how to view the contents of msdos.sys.
Remember I am using windows xp professional.

What are you trying to do as XP doesn't use MSODS?

The msdos.sys and autoexec.bat files are basically a placeholder. It is not used by XP, that's why they are blank.

If you want to edit the two files, you need to right-click on a dos program, and select properties, go to program tab, and click the advance button. There you can specify an autoexec file and config.sys file.