The First time I heard the beeps (constant rapid pulse) I did a Power button shutdown (Improper Shut down) as it had a black screen and nothing was responding, switching it back on from the improper shut down all was ok. All other times I have seen the windows boot manager has been because I have did a (windows) restart or the last time it had been because windows had completed an update and wanted to restart to coplete the update. The guy from HP help center sent me two links via email for driver updates, this was to test to see if these updates would cause the windows boot manager to come up during the restart part, which it didn't. Because of this we thought it might have been a windows problem?