Intelisense on C Doesn't work, but does on C++

[ziqiangao]

When I'm editing a C file, i don't a C logo or any error squiggles

[Colengms]

Hi @ziqiangao . Your file appears to have become associated with another extension:

This would say "C" if your file were associated with the C/C++ Extension as a C file. You should be able to switch the file association to C by clicking there and selecting "C", running the "Change Language Mode" command with the file open, or using files.associations settings.

[ziqiangao]

This fixed it, thanks!