Open Task Manager, type %systemroot%
and click "Ok". In the left pane of the window that opens, you should have access to "My Computer" and other areas where you have stored you information. You should be able to use this window to access anything you want to copy off the machine before you try the next option. I don't know that your machine will boot back up normally doing the next step...we may well have to start over tomorrow.
From Task Manager, type msconfig
and click "Ok". Under the General tab, select "Diagnostic Startup". Under the "Services" tab, tick the box at the bottom to "Hide all Microsoft Services", then click on "Disable All".
Click "Apply" then "Ok". You will be asked to restart. Let's go ahead and see if it will boot this way. If it will, we've got something to work with. If it won't, we'll start over tomorrow.