I had spent a lot of time to find a solution for this problem. As you know OllyDbg is a popular debugger but has a problem on Win7 x64.
every file (with different compilers!) that I open with the olly it replace some first lines with:
some advices like "comodo sandbox, compatibility" does't work and I don't want to use virtual machine.Answer1:
I had the same exact issue and managed to fix it. If you do indeed have comodo firewall installed, you have to uninstall it, reboot, then reinstall it. Make sure you NEVER, EVER turn on sandboxing again. For some reason, even with sandbox off, after its been activated on win7 x64, it STILL messes around with your software.Answer2:
According to the <a href="http://www.ollydbg.de/" rel="nofollow">OllyDbg homepage</a> and the <a href="http://www.ollydbg.de/version2.html" rel="nofollow">changelog of the current version</a>, OllyDbg does not support debugging 64-bit executables yet. It also seems that it has received no testing on Windows 64-bit, although it might still work for 32-bit executables.
It seems that for the time being you are out of luck...