Hi,
The first time I compiled ruby using the VS2010 express compiler for the first time and I got an error relating to the miniruby.exe.manifest file not being found. I changed the LDFLAGS in win32\Makefile.sub from:
LDFLAGS = -incremental:no -debug -opt:ref -opt:icf
to
LDFLAGS = -manifest -incremental:no -debug -opt:ref -opt:icf
And it works now.
All in all, pretty good experience compiling ruby on windows now, compared to most other packages I've tried to compile.