I have been getting frequent BSODs and need to find the minidump file. It doesn't appear to exist. I checked the entire c drive.
You may need to turn the dumps on in the Control Panel, as they're not always enabled by default.
The minidump files are usually located in
C:/Windows/Minidump/*.dmp and the full memory dump in
C:/Windows/MEMORY.dmp. Something should be logged in your Event log as well, including the STOP code and parameters.
It's important to call out that for various reasons, a dump won't be created even if you explicitly tell it to. The most common being lack of physical space on disk for the dump file, but if Windows doesn't trust the disk subsystem (e.g a storage driver went crazy and corrupted some kernel structures) then it won't try to write a dump, as doing so may do more harm than the usefulness of the diagnostic info would be.
If you have something like HP iLO then it may be able to record the last actions the system took and allow you to watch it back as a video, enabling you to see the STOP message and Google for more info. If you can catch it in the act of blue screening, I always find the phone on my camera is handy to document the STOP code and parameters.