I've been trying to change settings in Task Scheduler following this post (Conclusively stop wake timers from waking Windows 10 desktop) but on making my setting Windows asks me for a password for one of these accounts. To be honest I recognize none of the accounts (I do recognize my mail but I actually use an offline account and pin to log in. What are these and are there default passwords I can try?
You won't be able to provide any password there as the user S-1-5-18 is a system account. The PSExec tool from SysInternals can work around this issue by launching Task Scheduler as SYSTEM. Run this command in an elevated (admin)
cmd prompt to launch Task Scheduler:
psexec -i -d -s mmc taskschd.msc
Then proceed to modify the task as needed.