v10 upgrade - Windows 7 hangs at welcome screen

I just upgraded my system to v10 of parallels, I also updated my mac to Yosemite.
I have a snap shot of my VM saved. My windows 7 vm has all the latest windows updated and I just need to install parallel tools. The problem is after installing parallel tools, my vm restarts when I log in, windows 7 hangs on the welcome screen forever. I've reverted back to my snap shot several times and tried re-installing the tools every time with the same outcome, hanging on welcome screen.

Any help or insight on how I can get parallel tools installed and not run into the welcome hang bug would be greatly appreciated!

 

I was able to get my vm to start up properly using this support article - http://kb.parallels.com/en/8969

 

Hi Docket_Manager,
We are glad that your Virtual Machine starts fine now after following the actions in the above mentioned Knowledge base article.
Please feel free to reach us, if you have any questions. We are here to help you.