1. Your system may have troubles with booting up for various reasons, corrupted or missing system files is one of them.System File Checker
is a Windows utility that can fix those problems by replacing missing and corrupted windows files.
It could be run form command prompt in normal boot mode, safe mode and through recovery console.
I can't guarantee you that this will fix your problem, but it should be safe enough to try.http://www.winhelponline.com/blog/run-sfc-offline-windows-7-vista/
2. Another thing is the Search Toolbar you're referring to. It could help if you could tell us it's full name, what software exactly you where installing in order to get it, and what steps did you take to delete it (maybe you deleted a bit to much? ).
3. If you would successfully boot up in safe mode at some point think about running a Malwarebytes Anti-Malware scan. Just in case ;)