Looks like some people are experiencing a problem where the Metro screen is always skipped even after disabling or uninstalling Classic Shell. Here's a thread about it: http://www.classicshell.net/forum/viewt ... f=12&t=232
At the moment I have no clue what is causing the problem. Any additional info you can give me will be helpful - what version of Windows do you use, how long ago did you install Classic Shell, did you install any other software since then, did you install any Windows updates?
If you installed Classic Shell recently, you can try system restore to revert to the state right before the installation. Let me know if that fixes the problem.