Well, Windows 7 (Pro and above) will run M$ "Virtual PC". Addfitionally, they offer , "XP Mode" which is a licensed copy of Win XP Pro, SP-3...! (These are both free with Windows validation)! You just install them both, and run XP to your hearts content. You can even install XP programs in the virtual machine. That's the point of the whole endeavor , so please accept my apologies for stating the obvious.So, you can not only make it look like XP, it IS XP..!I tried to talk my wife into letting me upgrade her PC from XP to 7, but she would have none of it unless there was some sort of "classic" mode that looked just like XP. She was just used to it, since it was what she has used at home and work for the last several years. She had used my PC with 7 a little, but not enough to become familiar with it. But, she recently got a laptop with 7, and has been frustrated that there are things she can do with it that don't work with XP (like Windows Movie Maker not working with MPEG-2 on XP because of licensing issues), so I may have to ask again soon.
However, in another post, you mention having to install XP, to run a particular game. You might be able to run this inside "XP Mode" also. I don't however know, if any speed would be lost within the virtual environment. That said, Win 7 Pro, is only 30 dollars* more than "Windows 7 Home Premium", and that sounds like a strong bargaining position to me!
(*) The quoted $30.00 dollar difference is with OEM copies, IDK about the retail version(s).