I was able to do 'Find all reference' a couple of hours ago, and now suddenly it stopped working. When I do 'Find all references', its always says 'Search found 0 references'. I have reinstalled visual studio but the problem still exists.
Anyone has any idea what might be wrong?
Find all references generally only works when you have the project loaded. If you load a source file independently, it doesn't work. This also does not work across compiled libraries. Basically, if visual studio cannot resolve the reference using the source tree currently loaded, it will not work.
Delete the .ilk, .pch, and .pdb files in the Debug or Release subdirectory. Then do build all. It should reconstitute and work after that, especially after reinstalling VS.
try to find the "Find Symbol Results" windows (Ctrl-Alt-F12), its probably floating somewhere out of your windows (mine was near the status bar :)).