There is now a new RealSense SDK 2.0 available that works with Windows and Linux. It is based on the Librealsense SDK. Although it is primarily designed for the new D415 and D435 cameras, it is also SR300 compatible.
The recommended means of installing camera drivers for SDK 2.0 is to plug the camera into the USB port so that the drivers can be automatically downloaded and installed. The DCM should not be needed any more.
If previously suggested remedies and workarounds have not enabled your camera to work then installing the SDK 2.0 may not change this unfortunate situation. As the SR300 camera is due to be retired imminently, along with the R200 model, it is unlikely that further development work will be done on the SR300 drivers.
A .NET wrapper is planned for an upcoming version of SDK 2.0 but is apparently not in the launch version.
As the SR300 camera is due to be retired imminently, [...] it is unlikely that further development work will be done on the SR300 drivers.
This product was released in April 2016.
Why is the support lifecycle shorter than 2 years?
This is not the kind of behavior I was expecting from a company like Intel.
The RealSense cameras tend to be retired at some point after a new model appears that can duplicate their functions and also offer improved performance. F200 was replaced by SR300, and the ZR300 was a successor to R200.
If an older camera works well then the ending of driver support is not such a problem, as the most recent driver works fine for them. It is those who have issues with their camera and hope for a solution through updates who are unfortunately most affected by a model's end of life. I very much understand your frustration.
The imminent Windows Fall Creators Update may be helpful to you, as a user who has been documenting use of the SR300 with preview Windows builds before this Fall release reports consistent success with the SR300 after having problems with previous Windows builds.