Computer won't load to login screen

Last night while attempting to log off of computer an error message came up saying windows would need to close. Something about the win32 file. Mind you I just ha the internet installed on this computer late yesterday afternoon after not using this machine in about a year. The computer acts like it's loading and shows the windows screen but then never gets to the log in. I have tried safe mode, returning to OS something, tried going back to most recent normal start up and nothing seems to be working. Not sure if during Internet install something got messed up that wouldn't be seen until I tried rebooting. I'm at a loss any help would be appreciated. I don't mind resetting to yesterday morning even I just don't know enough to get it there
thanks for any help