Norton Utilities Defrag and BSOD help Windows 7

Hi,

 

I have done a search for this problem and have come to some solutions but still need help. Essentally I cannot boot Windows  7 64 bit after I compacted some of the registries. Here is the link I found helpful. However I cannot seem to access my C: from the X command prompt,

 

http://community.norton.com/t5/Other-Norton-Products/NU-15-is-deadly-for-System-7-64/td-p/659677/page/2

 

I have tried to follow Dave's solution. However when I type C: that works, but when I type cd windows I get a "the system cannot find the path specified"

 

My local disk where Windows 7 is installed is on the C drive. I tried the command prompt from the Windows 7 cd and also from the Repair tool that pops up after windows crashed.

 

Any help is appreciated. Thanks.