Hi there and welcome to LQ!
For future reference threads with titles such as 'help' or 'urgent' or anything lacking information are usually glossed over. By providing a title like 'installing windows on a redhat machine' you will get people who know what they are doing in that particular subject. That being said:
As far as I know, it is much easier to have windows be installed first then install linux (computers have a tough time doing it the other way.) Maybe back up your important stuff, Install windows, and then reinstall linux.
You could get Virtualbox (or any other virtual program) and set up windows on that. It will run Windows on a pretend machine WITHIN linux.
I've read recently about how to do a windows install on a Linux machine, But do not remember the steps, and don't want to try
... I will look for the link on the board and if I find it will post it.
Please note, I am a linux noob ... and these are all things I have seen others suggest at some point ... I am capable of mis-wording so look into it. Google is a most useful tool (Although with linux stuff it always seems to lead here
) I wish you good luck, and enjoy your time here.