Flash player crashes 100%

The most likely cause is problematic graphics drivers.  If you disable hardware acceleration and the problem goes away, then find the latest drivers for your graphics hardware, and re-enable hardware acceleration for optimal performance.  If the problem comes back, you'll need to disable hardware acceleration again, and wait for a future driver update.

Instructions on how to do this are in the video troubleshooting guide, below:

https://helpx.adobe.com/flash-player/kb/video-playback-issues.html

If disabling hardware acceleration doesn't help, the Firefox crash report should tell me what's going on.

I *would* highly recommend that you upgrade to 64-bit Firefox.  (You get 32-bit Firefox by default.)  You'll get a much better experience from Flash and Firefox in terms of stability, performance and security.  Just choose the English download in the 64-bit Windows column.

https://www.mozilla.org/en-US/firefox/all/

Moving to 64-bit Firefox will solve the vast majority of common Flash/Firefox crashes.

If the problem still persists at that point, links to a couple crash reports should tell us what's going on.

In firefox, go to: about:crashes

Click the first couple links to submit them (you don't have to wait for the report to display), then right-click on the submitted links, choose Copy Link Location, and paste them in a reply here.  I'd be happy to take a look.

Thanks!