I was in server hell this weekend, as I was trying to upgrade a machine from 2008 to 2008 R2.
I had more problems than I could even write on this page, but most were unrelated to the actual upgrade itself.
The one thing I wanted to put here was regarding the fact that the update seemed to hang at 62% in the final step.
At one point I walked away and came back like an hour later to find it still at 62%. I swore a bunch of times and left the computer running while I went back to my laptop to try researching the issue.
I found that there is a known issue in Windows 7 upgrade that causes it to lockup at 62%. I figured I had something like that happening to me, but thankfully I didn’t pull the plug too early because sometime during the next 30 min or so, it moved to 63%, and soon it was done.
So, if you are upgrading to R2 and you are stuck at 62%, or 63% (63% took a long time too), don’t pull the plug. Let it sit for another hour.