I see no action happening and I think it froze because I can't do anything.
If I try to quit it tells me to wait until test is done.
Thanks

The Surface Scan is a read-only test. You can safely force quit TechTool Pro as long as the Surface Scan is the only part of it that you have running.

I will post the same suggestion for the three problems you have reported:

Please repair permissions with Disk Utility, and then reinstall TechTool Pro 8.0.1 The installer is in your Available Downloads, at the bottom of the My Account page, linked above.

If the program does not run properly then, please send a message including a link to this thread to This email address is being protected from spambots. You need JavaScript enabled to view it. . You will receive a reply by email. Thank you.

Check Computer has been running for 24 hours. I have hit the X to quit the remaining tests but still running.

The tests in the Check Computer suite of tests are read-only. You can force the TechTool Pro application to quit:

How to force an app to quit on your Mac. If that does not work, try launching Activity Monitor, in /Applications/Utilities, and use its X button after selecting the TechTool Pro application in the window.