You will need to contact Customer Support. This is a user to user forum - rarely staff come on the forums to comment.
I don't think any of the usual forum posters are qualified or in a position to answer to your question.
You cannot convert applications. You need to crossgrade (if your version would be the latest) or to upgrade to the latest version. You need to upgrade either to CS6 or CC.
Your files should not make problems, except for fonts which might not be available on the other operating system.
To summarize, Adobe only allows this for current versions so you have two things going against you.
1. You have an old version.
2. There is no upgrade pricing
Your choices are to buy a full CS6 license or move to Creative Cloud. Creative Cloud has the benefit of being crossplatform and your CS4 license qualifies you for intro pricing of $29.99/month for the first year.