Windows 7 - URGENT: Can I interrupt installation

I recently did a clean install of Win 7 Ultimate. However I was having problems with registry and decided to do an upgrade re-install. It seems to be stuck at 63% transferring files, settings and programs for the past 6 hours.

Should I interrupt by powering off?

If I do this will I be able to get to my docs to save before doing a clean install?

Please help ASAP...going crazy

Sounds like you don't have a choice at this point something has hung

Files should be saved before any upgrade, installation or repair operation. They fail all the time.

There is a chance it will rollback when you shutdown by holding power button in.

If not, you need to call MS if you have a retail copy to get the rollback support. You paid for it with your copy.

If this is not an option for you, then boot the Windows 7 DVD Repair console to see if it finds an installation to repair, click through to Recovery Tools list and run Startup Repair repeatedly to try to start it up.

Tried powering off. It is rolling back. What a relief!!! I will now backup files and do a clean install. I think my original problem might have been caused by overusing a registry cleaner, Advanced System Optimizer. I am now scared of using a registry cleaner. Mayber Ccleaner is safer???

The only tools I use after a year on Windows 7 are the state-of-the-art CCleaner for its Disk and Registry cleaners, and Auslogics Disk and Registry defraggers.

These are the most highly regarded in the industry, free, and flawless after 10 years use.

Thanks for help and suggestions. In future I will stick with Ccleaner