I can not access the Macbook pro after using guest account
The only thing that works is safari.
Apple only gives the options: restart, shut down and startup disk
and that doesn't help me any further.
Who can?
MacBook Pro, OS X Yosemite (10.10.1)
On the log in screen do you see two accounts, yours and a guest? If you only see the guest account this thread, while old, could help: