+1....yes, if possible exchange for the 64 bit version of W7. I a few years 32 bit operating systems will be gone. If you can afford it, a retail OS disk is the best thing over an OEM upgrade. In addition, if you ever decide to get a new computer (possibly build one yourself) you have the freedom to install Windows 7 on the new computer from your disc legally and M/Soft will recognize it. You cannot do that with an OEM "bought from the store" OS already installed by the manufacturer.
The thing to make sure of first, however, is have all the drivers for your motherboard, chipset drivers, sound, video and all others, because you will have to install them or some of your components may not work otherwise. Before you do a clean install or upgrade of W7, go to the computer manufacturer's website and hopefully they have posted the drivers for Windows 7 for your machine. Sometimes you get lucky and the drivers for Vista will also work on W7, but best to play it safe.