"only" ??? I dont think so.

The old command doesnt work, yes, but does ;)

I know this for sure because I somehow deleted everything in C:\ the other day (not subfolders thank god!) so I had to copy stuff to C:\.

The recovery console wouldn't be very effective if you were only allowed into \windows\

So try again using "cd[space][backslash]" to get back.
or at any rate "cd .." works.