Dual Boot System - RTM Partition No Longer Available

I created a dual boot system quite some time ago and all was well until . . .

RTM partition was completely up-to-date. I had recently updated to Windows 10 Build 10251 on the Insider partition.

I turned the machine off on Sunday January 31, left town, and returned Saturday February 6. All was well with the dual boot when I turned the system off before leaving. When I turned the system on last night, it booted directly into the Insider Partition. There seems to be no option to boot into the RTM partition.

Help!

Does the RTM partition still exist? If it does, IMO, it's only missing from boot manager.

Does the RTM partition still exist? If it does, IMO, it's only missing from boot manager.

Yep, I checked and it's still there (D:). And I know nothing about the boot manager.

Press Win+R, type in -> msconfig<- Enter. Click on Boottab, does the RTM is listed there? If it does, look at the Timeoutbox, the reading should be 30seconds.

msconfig method should fix the issue.

Just to add..................
Control Panel > Power Options > left side, Require password on wakeup > Change settings that are currently unavailable >scroll down, UN-check "Turn on fast boot startup" > Save changes.

Press Win+R, type in -> msconfig<- Enter. Click on Boottab, does the RTM is listed there? If it does, look at the Timeoutbox, the reading should be 30seconds.

Thanks, Private; that worked!

msconfig method should fix the issue.

Just to add..................
Control Panel > Power Options > left side, Require password on wakeup > Change settings that are currently unavailable >scroll down, UN-check "Turn on fast boot startup" > Save changes.

Thanks, David. Private's solution worked. So, if I'm reading this correctly, fast boot could be the culprit? But, but, but, I like fast boot.

My next question would be, "Has anyone else with a dual boot system had this problem or is this one mine alone? Should I send feedback?"

My next question would be, "Has anyone else with a dual boot system had this problem or is this one mine alone? Should I send feedback?"

No, you are not alone.
I have seen a few threads related to that.
Personally I had the same issue. I dual booted Win 10 and Linux and it rebooted to Linus automatically.
msconfig is the solution.
Also under msconfig > Boot > I would set the OS I use most Set as default.

No, you are not alone.
I have seen a few threads related to that.
Personally I had the same issue. I dual booted Win 10 and Linux and it rebooted to Linus automatically.
msconfig is the solution.

Thanks, David! Feedback imminent!

Also under msconfig > Boot > I would set the OS I use most Set as default.

FWIW, for me, the most recent "installation" remains the default boot OS. Since RTM was the first installed, and I haven't clean installed it since the "November Release", each new build that's clean installed becomes the default; if I don't choose one or the other, the default boots.

Yes, the "latest" install becomes the default.
That is why I mentioned about choosing which oneyou want as default. You might not want Insider build as default.