NullDevice,

I thank you for yours and Sirdice' suggestions. This is not to create viruses but to understand how they work.I will make use of for writing some useful programs.

In the mean time apart from TSRs, is there any other way to create memory resident programs in windows?(i.e what is the Windows equivalent for this)

Inadvertently I gave rating to my own article-so please excuse me.

Chokks.