mandrake 9.1 not booting
 

after setting up my lan connection the physical ip address to my lan card changed ,since than linux doesnt boot
in boot doesnt freeze but just doesnt go further than checking new hardware

When it is booting, there is likely to be an option (be quick, it is near the beginning) to 'enter interactive mode'. If you can, do it. You should be able to skip the 'checking for new hardware' bit then.

If not, then press escape when you get to the bootloader (to stop it from booting automatically). Type in something like linux 1 to boot Linux into runlevel 1. From there, you can manually remove the entry in your init scripts that causes the 'checking for new hardware' line. It much harder than being quick on the keyboard :D