Acer Aspire One with 10 tech preview can't restore

Hello everyone. First time I've posted on a forum, and not exactly a newbie at this but I am seriously confused. I downloaded the win 10 preview a while back on my Acer Aspire netbook with Windows 8 upgraded to 8.1, to show some people what it is all about. Now, I would like to update to Windows 10 but cannot restore the netbook back to 8.1 to enable win 10 upgrade. I cannot access the hidden restore partition, if it still exists, and no amount of F2, F8, or F12 will get me anywhere. I did force the netbook to get me into system repair, and I was able to get to the restore options, but when I attempted restore to factory settings, it said files where missing, and to insert my recovery media to fix this. I have no media to use for this, and the only option it gave me was "cancel". I would really like to get this back to 8.1 so I can reserve and download 10. Help??

All help is appreciated, and I thank you all in advance.

First run Winver - if it gives you build 10240, you are on final the version of Windows 10.

Then, from an elevated command prompt, type slmgr /xpr. If it says permanently activated - that's what it means, your activation will never expire. If both those conditions exist - permanently activated build 10240 - that is exactly what you would upgrade to anyway.

If you have an earlier build, with an activation that is permanent, you can just use the Media Creation Tool to get the build 10240 ISO and upgrade from that.
Windows 10

Otherwise you need to create a Windows 8.1 install media and clean install Windows 8.1:
How to Download Windows 10, 7, 8, and 8.1 Install Media Legally