Ok so i fixed the same problem and will provide a step by step way to fix it.
1) Right click start button and click search
2) search system configuration and click
3) goto services tab
4) check the hide all microsoft services
5) then select disable all only after the previous step's box is checked or you will * * up
6) then click startup tab and open the task manager through the link in that tab.
7) disable everything to start with.
8) go back to system config window and click ok, a popup will appear and click the restart button.
9) once restarted try APEX Legends again.
10) if this works you and enable items one at a time at step 5 and 7 to test and see which item is causing the problem and remove it.
Hope this fixes it for you. if it does then the problem is one of the items you disable may contain malware and should be removed. so i HIGHLY recommend testing to see what is causing it. otherwise you can just run it with minimal background apps and processes from now on.