well i think it is up to you. I have done an upgrade from Vista to 7 on one of my friend's computers and it worked fine. There are some people though who say a clean install is better. I think both work but when doing a clean install make sure to back up the files you want to keep.
I had the same thing happen to me even though I used Sleep or Hibernate. I guess the lock is used to protect your computer from other people messing with you files.
I am confused on when I watch a video online on Cosmeo. The video's audio is going too fast and the closed captioning option does not work. I used Cosmeo on Windows XP Mode's Internet Explorer. Can any one help me?:confused::(