I'm assuming here that you have either Winzip or the Winrar programme to compress this file that you have?
I would suggest that out of the two, I would use WinRaR as this is a more recent and more popular compression programme as used by users..
If so, to compress a file into either format first highlight the files that you want compressing using the left mouse button.
If its more than one file you want to compress, e.g mp3 files of an album etc, hold down the
'ctrl' button whilst clicking on each file using the
left mouse button.
After that
click on any of the files highlighted using the right mouse button.
This should bring up some options. Look down and you should see a option called 'add to archive'.
Click on the
'add to archive' button. From there, it gives you the option of renaming your file here if you wish. Now press 'ok' and the compression should now start. Hope this may be of help to you.
For these compression programmes, you could either go to:
www.winzip.com or
www.winrar.com
Any problems, just holla.