Well put it this way. If you have the drive visible and able to be accessed by Windows when in use, meaning that it shows up as the D:\ Drive or whatever and you can browse it, what is to stop an infection from going to that drive?
Think about it. Infections are known for their ability to infect systems with just access. USB Thumb Drives are notorious for infecting system with just being plugged in. So having the drive be accessible is the same thing as hooking up a infected USB Thumb Drive.
So yes it is very simple to say that the Recovery Partition is compromised when you think of that. This is why those Recovery Partitions need to stay hidden from the view of Windows to stay effective.
Even then you get a Trial version of a anti-virus solution with them and it is as old as your PC is. So the definitions are out of date from the second you start the restore process. So you would have to disconnect from the internet, restore, remove the old AV, install the new AV, then hook back up and update. Only then could you be at least moderately protected.
Its not going to be any different if you use Win7, XP, Server 2008, or any other Windows OS. the second you get infected you need to take EVERY step to get it removed and protect yourself from it happening again. No matter WHAT OS YOU USE. going to Win7 isnt going to resolve all of your issues.