There are some problems with your question, although I think I know what you're getting at.
About the part of "burning two windows onto one dvd" -- the answer is that burning windows itself onto any other dvd is illegal.
However, it sounds like what you may be asking is "how do I get my computer to where I can run two different versions of Windows (such as XP and Vista)." If this is what you're asking then the answer is to have "dual boot" configuration.
Some helpful, but technical information may be found at
I do not mean to insult you, but it sounds like your first language may not be english (although I'm sure that I am very bad at your language, if this is the case). If so, you may need some assistance from someone you know in reading the complicated webpage given above.
In the future, it may help to give longer explanations of what you would like help with -- it's not so much that your english is weak, it's that your question is so short, and has little detail.