Optiplex 755

Now it’s working.

sent from my iPad.

Never heard of Dual boot and therefore not what I want. I just want to be able to get to both drives from boot menu. I am assuming this is possible if everything works. However, the 2nd drive is not showing up in the boot menu so 2nd drive is inaccessible.

Also I DO NOT WANT TO USE WINDOWS 10, as I have said several times. I tried it and burned up my whole 3Gb data for the month jin about an hour, before I could figure out what to disconnect from the internet. Sent the computer back, the DVD was not working anyway. I hate W10, don't need to be connected every moment on my computer and don't want to send anything to the Cloud. 

I am keeping W7 to use the programs there and using Linux to get to internet so I don't have to worry about updates and security.

OK? whether you like that or not that is where I am.

Thanks for reporting back here Dot. It's nice to know the end results. Often, people just disappear afterwards. Or perhaps they were run off ?   

Glad you got it working, and I wish I could have been more help, but my knowledge is very limited.

Something that might be handy:  Optiplex 755 Tech Guide 

In the Boot Menu, where it shows "SATA Drive," if you hit enter on it, does it then show 2 drives (with both hooked up) or does it just go right to one of the SATA drives?

What made me think of it - Normally I've seen more detail, like a model # with the drive; whereas on your Boot Menu screen it just shows "SATA Drive."

It goes to SATA0 drive.

In storage mgmt there is an option to make that drive “dynamic” but says that will destroy the o.s.

Huh, I guess at least it's closer to working than it was before; just not the way we expected.

So is that it?

OK. Thanks for your help.

You're  welcome and thanks for accepting my post as a solution.

DUAL booting, google that and read.. please..   (read then ask questions is best)

that is what you  long posts never said then said what is DUAL boot last.

Your BIOS is not a boot manager,at all (but you learned that forcing boots in BIOS can be done in A22)

GOOGLE Dual booting Windows and Linux, see the endless problems  on modern PC and UEFI issues.

Is that it ?  well only you know that, nobody can know  what you really want or expect, for sure. (not once told)

If you had newer PC, (CPU) with Hyper-v features you could run Linux as  image boot. from W7.(or W10)

Ok now you know how to force boots in BIOS, (the disablement of ports trick) so.., SOLVED THIS IS?

your MT has 5 SATA ports, plenty if one fails you can USE another, if you use   BIOS to do that. 

below is the MT motherboard with 5 SATA ports  that is why we ask (one reason) what case you have.

so if ONE FAILS we can switch to another, the PC wants to  boot on the blue slot, and as you learned it can be forced, in  tedious way.   ports can be enabled or disable and boot order too. IN BIOS... that is all you get..

This is the full sized PC case, called MT  called MiniTower, the best of them all for future upgrades..

Link given by savvy2 is for dual booting from one HDD.  Dot has 2 HDD's, one with Win7 and one with Linux.

yes many pages show 2 HDD beyond scope of this document, yes..

the rules for using 2 drive to boot are also covered in windows and linux.

both,. w7, not W10.

they need to google to learn that.

the trick is the limits of W7, BCDEdit limits, for sure.  OR EasyBCD.exe (clean) click register.

google dual boot with 2 drives, finds them, in clear text easy search.

w7 only,. and linux and 2 HDD.  ezbcd is the most easy way and is 100% safe for malware.

FOUND IT here at MS.

After installing it, go to the Add/Remove Entries Tab >

Add Entry at the bottom.

From the drop-down Linux Tab select Grub, give it a meaningful name and point it to the appropriate drive. Click tab linux/bcd , for sure ONLY you know what linux you run and what boot loader it uses .Grub1,2 or Lilo. then what  linux drive, D:?  and then what partition GRUB resides.

dual booting W7 goes back to year 2007 .so NO LACK of examples ever on topic.

Well 2 years ago you were a novice, but what you were trying to do was Dual boot. I see no one explained the the concept here.