Yeah, good old restart loop here too.
"windows has encountered a critical error and will restart in one minute"
And yes, it's avast.
Unfortunately complaints without details and a willingness to supply information will not resolve the problem or help anyone
including your own problem.

Hi,
Regarding my earlier post about an endless reboot loop with this version of Avast! Free, here are some details:
- Windows 7 Ultimate x64
- New Windows installation to an empty 120GB SSD, only Windows Updates installed (and Mozilla Firefox)
- Obviously, no previous version or security software
- According to ntbtlog.txt the last driver to load before reboot is mrxsmb20.sys
- Have had to use system restore to be able to boot to Windows
Let me know if you need some additional information.