I'm having this issue as well, but I don't see an HWiNFO entry in Task Scheduler.
I have disabled the auto-start option and clicked OK, and I enabled the auto-start option and clicked OK, and still no entry in the windows task scheduler.
The only antivirus/antimalware software I have running is Windows Defender.
Would installing HWiNFO to a 'non-standard' location (for example if Windows says my programs folder is on C:\Program Files, but I have installed HWiNFO to D:\Program Files) cause it to install as a portable edition?
That should not be an issue.
If you don't see the "HWiNFO-Sch.xml" file in your %temp% folder even after disabling/enabling Auto Start, it could mean something is preventing HWiNFO64 from accessing the %temp% folder.
This might be a heisenbug? Last night it did not create a HWiNFO-Sch.xml file in %temp%, but today, when you mentioned that something could be preventing HWiNFO from accessing the %temp% folder I couldn't think of a thing that would cause that. So I went to make a Procmon log of the operation to see if there was something in that, and it worked during the logging. I haven't restarted yet, but there is a HWiNFO-Sch.xml file in %temp% and there is an entry for HWiNFO in Task Scheduler.
Thanks to this thread, I got the AutoStart working with the new beta as it was basically what post #4 said and then checking task scheduler to confirm the HWinfo entry and then rebooting to make sure it works after manually running the task before rebooting.