Can I upgrade Windows Vista OEM TO Windows 7 using anOEM CD?

If I purchase an OEM version of the appropriate Windows 7, will it allow me to do an upgrade? I believe it just images the cd to the drive over-writing the stuff on the drive, but I thought I’d confirm with the pro’s (you guys!)
I don’t think it will, but if I could save a few bucks, I would love to…
Thanks in advance!
Answer #1
Does your Motherboard support Windows 7 Legally?
See, The thing is Dell – They are giving away free Windows 7 Support for Few Laptops & If you happen to be one of them. Then it won’t ask you anything in Installation & your Installation would be Updated Genuine Automatically.
If you don’t fall into this category still you can do it, But you will get 30 days and you will have to use WGA to patch it up
But Basically Yes you can do it.
(Do-NOT forget to select upgrade option while installation & Run the installation from VISTA )
Answer #2
Well, the laptop I am working with is a Sony Vaio that came with Vista pre-installed. I don’t fully understand your argument regarding Dell; I’ve used OEM disks in the past with no trouble. For instance, I have an asus mobo for my desktop pc, and installed Windows 7 on it via an OEM version – valid serial number (I bought it). I haven’t had any issues with it – have I just been lucky?!
I’m skeptical about your answer now and am thinking that I’ll just need to buy the upgrade. If anyone else has input, it would be appreciated!