How much of that 20 minutes consists of booting Windows, and how much of it consists of running the myriad policies, scripts, and startup software that "enterprise" environments push out to all their systems and run on every boot? Not exactly a fan of Windows, and newer versions often do boot slower due to added bloat, but you can't chalk 20 minutes up to Windows alone.
It shouldn't be that bad. I've seen university machines running windows 7 with less than current hardware and a whole bunch of scripts, antivirus, etc, and they still boot and shutdown in a very reasonable amount of times. Definitely sounds like the hardware rather than the myriad of scripts to me. Shrug.
But conversely, there's nothing wrong with a computer of that spec, if you're doing web browsing, word processing and the like. It's just not being used efficiently.
And it was just yesterday when I stopped being a hardcore gamer and knowing about computer specs, and that spec wasn't half bad. Am I locked forever thinking that would be a decent computer?
I'm having the hardest time believing you said that with a straight face.