pls answer to the question asap

You can try doing a repair with the cd if you have one or you can do a restore to a date in which you know you where not having that problem.

The config.sys file was used by earlier versions of Windows to define device drivers, disk cache settings, etc. Windows 2000 and Windows XP don't use the file, and it can be safely deleted.

with your Windows XP operating system, the Config.nt file is used for the same kind of tasks formerly performed by Config.sys.

My guess is that the file is left-over from an earlier version of Windows, if you upgraded, or it was created by an older program that someone installed or attempted to install.

Config.sys is located on the root of your C: drive. Open the file up in a text editor like Notepad. See what the line line one in the file is. You may even want to just remove the line (after making a backup of the file first.) Or rename the config .sys file entirely as it is not necesary for XP. Make a not of any program or devices that have a problem after removing, renaming or modifying the config.sys file.

Open the file in a text editor and remark the line by typing rem in the first 3 characters.

You probably won't need the line, but a remark will let you bring it back should you need it back.

Good Luck