You posted in Windows 7 forum.
So, your OS is Windows 7.
Perhaps, you wanted to know what "version" of Windows 7 you have?
In any event, please follow this......
Start button > right side, click Computer > toolbar at top, click System Properties > under Windows Edition, it tells you what you have, including whether you have service pack installed or not.
I'm sorry. I didn't explain my question very well. Your right, I'm running Windows 7 now. My question was, I bought this computer back in about 2007 and would like to know what OS I have installed over the years? I think I've had at least 2 upgrades. Is there some file somewhere that would tell me that? Thanks
There's really no way to tell. You can only find out what the current OS is installed, from with in Windows itself. You could do some detective work. Check the PC's vendors website, cross reference make/model number and see what original OS was installed by checking what drivers are avaiable for what OS and compare that to what OS you've and kind of guess how many in-between was installed. The only other way, would be a paper trail. If you kept all your OS purchases, you'd know.
If you bought it new in 2007, more than likely it came with some version of Vista. If you bought it used, still more than likely Vista but better chances it would be some flavor of XP as a lot of people despised Vista when it came out.