repairing registry errors whilst in dos HELP please

I installed a piece of S/W from nokia last night for my phone, and on re-boot it keeps sending the lappy into blue screen of death re-boot loop.

all i catch before the re-boot occurrs is that there is a registry problem im assuming its from the new s/w

I have tried to fixit with a dos application but it's not working

can anyone suggest a dos repair or a way to do system restore from dos/setup?

cheers in adavance!

 

http://support.microsoft.com/kb/307545