If your DVR is beeping non stop, follow this guide in order to disable all of the alarms.
Step 1: Right click on the mouse and select 'Main Menu'
Step 2: Select Advanced
Step 3: Select Alarm
Step 4: Change 'Alarm Manage Output' to 0S and also change 'Buzzer' to 0S
Step 5: Hit 'Apply' at the bottom of the page
Step 6: Hit 'Ok' when the system says 'Save Successfully'
The alarms on the DVR should have stopped beeping now.