WaasMedic Agent Exe stopping me from working

i have also been having this issue, most recently its been a system app called system.exe(defrag) it has to do with maintenance being done automatically by the system. i figured out there are three things doing this and if you go into task manager and go to services and open services you can go down the list till you find the windows search service and right click and go to properties and end task and disable it also do the same with superfetch and  sysmain. or if you prefer on your keyboard press windows key type command prompt then select run as admin, click yes to allow. the command prompt will display enter command net.exe stop "windows search" this will stop the system program from running. you can do the same with the other two system programs and see if that fixes your problem. hope this helps good luck.

Different issue, and possibly a better way to fix it. I THINK you are witnessing impacts of Windows auto-defragging and "indexing".  Open "Settings", type "Optimize Drives" into the search bar. In the resulting panel you will likely see "Scheduled optimization" is ON.  Click the chang settings button and you can turn optimization (defragmentation) on or off, or change the schedule and action if it misses scheduled runs.  You can also choose which drives are "optimized" and which will not be.

You can also right click a drive in Explorer, select properties, go to the "Tools" tab of the drive's properties window click the "Optimize" button and get to the defrag enabling / scheduling pane.

For indexing, in the settings search bar type "index" and select "Exclude Folders from being indexed" or (Choose which files and folders are indexed" etc.  In the resulting pane you can choose the extent of indexing or with the "Add an excluded folder" control, turn off indexing for any or all your drives or remove folders from the indexing exclusion list.

This may impact some  of your startup times, but does not address the daily, crippling run of WaasMedicAgent due to the varaious Windows Update bugs.

Thank you! My problem was opposite, I had to plug in my external drive to get the problem to go away.

Did you ever find out how to fix this?? 270 other people with the same question and not one reply.

I have the same issue now and my PC is currently unusable. 

I was hoping it would fix itself and the app stop running after a while but my disk usage is at 100% constantly.

Is it safe to just end the process??

Bit of a joke really from Microsoft when there's no warnings or prompts, just take over my PC.

Is it safe to just end the process?? 

I don't know, but its what i do every time it uses up all my disk. So far i haven't experienced any problem by ending the task but we surely need an answer to this problem.

I have WaasAgent using 100% of disk space per Task Manager, but no external drive plugged in.