Computer help forum: IBM Thinkpad problem

Basically your OS install is corrupt, leaving you with two choices:

1: You can try a repair install, which leaves your data intact, but you will almost certainly need to reinstall all your programs

2: You can format the drive and start with a fresh install. You lose all data and programs this way (which is why you have backups), but it's a clean break, and a chance to start fresh

but the last I remember as IBM branded were the T-40 series. They became Lenovo after that. In any event, if yours was a factory installation, you should have a recovery partition and a Lenovo tool to do either a full or a repair installation. You didn't provide the model number so we really don't know how old yours is. It's a matter of pressing a key or two doing startup which will bring you to an options menu. If you cannot even get into safe mode, you can possibly recover your data before blowing things away. You can either boot from some Linux live CD (which you'd have to make from another PC) or you could put the hard drive in a USB external case and access it from another computer.

ThinkVantage button immediately after the Splash screen. You will be given the options there.