Dell OS Recovery Tool USB not bootable (Optiplex 790)

Your Optiplex 790 should have Legacy BIOS option. Try selecting that option. 

Thanks for the reply. I have set the 'Boot list option' to Legacy. This doesn't change anything.  The Optiplex 7010 has an option (I think it was in "Advanced configuration") "Enable legacy option ROMs'. The 790 doesn't seem to have this, but I seem to remember this was something that had to be disabled if you wanted Secure Boot, which the 790 does not have - so this is probably why it is not present.

@SteveJS 

You must use USB 2.0 FAT32  16 or 32 gig flash drive.

Sandisk 32gb usb 2.0 flash drive  skuId=9288807

These are not expensive and work fine when you buy retail so that its not fake USB.

7 isn't viable and is no longer supported.

10 works fine but you must use the Media creation tool to make 32 bit windows 10 installer.

Unless you actually need 32 bit windows its not advisable to install that.

You can also use rufus to make windows 11 installer that works fine.

rufus 3.18 

Sata operation in bios should be set to AHCI.

Media Creation Tool

https://go.microsoft.com/fwlink/?LinkId=691209

Is BIOS set to AHCI?

Try replacing the size 2032 CMOS battery if it's 5+ years old.

If still no luck, it might be a better to load from a DVD.

Thanks all. BIOS is set to AHCI and I had already changed the CMOS battery - it was completely dead.

Windows 7 is only for messing with, but does seem quite good for general use. I don't have, or am likely to have , the hardware for Win 11! I would prefer to install 64-bit, because some programs don't have a 32-bit option, but the 32-bit Win 7 is the only one offered by the Dell OS recovery tool for this machine.

The computer does have  a product-key sticker, but it has been my previous experience that these don't seem to work, so I am aiming to try that as a last resort. Would the product-key be 32-bit/64-bit dependent, or, if it does work, would it work on either?

The machine boots perfectly OK on the Win7 64-bit USB downloaded on the 7010 Service Tag, but I am assuming (correct me if I am wrong) that this would not create a legally fully 'activated' OS on the 'wrong' machine. Comparing the root of the two USB stcks, the 64-bit has one extra file, bootmgr.efi

32-BIT:

64-BIT:

I tried copying the bootmgr.efi from the 64-bit to the 32-bit, but this did not help.

@SteveJS 

1. There is No conversion from 32 bit to 64 or the other way round for ANY version of windows.

2.  Only OEM DELL windows 7 activates without asking for a key.  And only if your bios has SLP KEY for Home or Pro windows 7.

3.  Non Dell OEM windows 7 requires the COA KEY to activate.  32 or 64 bit is not relevant to activation the KEY is the same for 32 or 64 bit.

4  Windows 7 is End of Life End of Support from Microsoft and Dell.  Windows 8 is also end of life End of Support.  Only windows 8.1 or 10 is still supported.   If you have your WIN7 COA key you can install 10 with the "I don't have a key" option during install and then use the WIN7 Home or PRO key to activate once you get online.

5.  Only the windows version that came with your model is supported.  Not supported does not mean not working.   Even windows 11 can be installed using the I dont have a key option using RUFUS 3.18 and it will work.

6. Drivers for this model are VISTA or Windows 7 drivers.  There WILL NEVER BE Windows 10 or 11 drivers but the 7 drivers cab works fine with 10 or 11.

Best way for recovery is using OEM Windows 10 DVD F12 boot the disk and install 10. I suggest buying this now because after they are gone they will NEVER be available again.  The Refurbisher program from microsoft ended and no new media is being made.

One dvd can be used to legally install windows on any dell model that meets the minimum spec for 10.  Rufus can be used to make special USB 2.0 FAT32  32 gig installer for 11 that does not require secure boot or TPM.

WIN10 reinstall recovery disc  N82E16832350238

DELL KB 000122062 optiplex 790 windows 7 driver cab

790 win7 A08 34RKD.CAB

I believe I have found a way of getting working Dell recovery media  for the Win 7 32-bit OS on this machine. I went to the Dell OS Recovery Tool pages on a Linux machine and after entering the System Tag I was able to download the ISO. I copied this to a Windows machine and used Rufus to create the USB. I still have the BIOS in the Optiplex 790 set to UEFI  boot, and no UEFI option appears in the F12 menu when the new USB stick is installed, but the "USB storage device"  option under Legacy options does now work, and the machine boots into Windows setup.

I will attempt installation later, and report back if it is successful.

Steve.

The first attempt went OK until it got to the first reboot, when it should have been booting to HDD, and it said "No bootable devices". Evidentally it does not see the HDD as a UEFI device. Why would this be? Changing to Legacy boot fixed this and install went OK.

I thought I had read that with the Dell recovery media the OS would be ready-activated, but it wanted a Product Key, and I gave it the one on the case. I attempted to activate online, but it said I needed to use the automated phone system. I expected I would be activating the Win 7 OS, but the instructions were only talking about Windows 10 and I abandoned it for the time being.

Thanks, speedstep, for all the useful information above. If I was installing Windows 10, it would be on the 7010. So are you saying that if I installed Windows 10 Pro on the 7010, the Windows 7 Pro key would work, or would it only be valid on the 790? I find all this extremely confusing, as you can probably tell!

790 has early UEFI.  I also have a 790 DT.

If you use the "I don't have a product key option," it'll use the product key imbedded in BIOS.  If it's valid or accepted, all you have to do is activate the OS online.

I'm not 100% on why it had to be changed to Legacy to accept booting.  What I do know (pardon, I'm referencing 7010 due to experience) is when Secure Boot is on, BIOS and Boot Menu don't show me all of the drives, though the system knows they are there.  But if Secure Boot is off and Legacy Option ROMs on, both menus show be all the drives.  I never figured out a rhyme or reason for it.  Yet, my bootable drives were loaded with UEFI and Secure Boot on.

This is not meant to cause confusion, as if I remember right, 790 doesn't have Secure Boot.

@SteveJS 

790 is not 7010

790 DOES NOT HAVE UEFI

You cannot use windows 7 key from one machine on another.  If it asked for key installing windows this means it has VISTA COA Key and VISTA SLP Key in bios.

No vista keys are compatible with windows 7 or 8 or 10 etc.

Windows 10 current version will install "without a key" on most dells at least Pentium D 900 series or greater from 2006 to now.

Install is NOT activate however.  You need windows 7 home or Pro key to activate windows 10.

I'm thinking either should be fine, though I'm not 100% sure..  Still choose "I don't have a product key" when it asks for one and it'll continue with install.  After attempting to activate online, if it doesn't work, then it might ask for a product key.  Try the one on your PC sticker first.

A little fyi - I was going to use Win7 for Windows Media Player since later versions of Win10 have a bug in it.  I loaded a disk with Win7 SP1.  I couldn't even change taskbar and other colors.  Internet was difficult as many websites don't work with old browsers, though I managed to download Chrome.  Win7 just isn't the same without the updates.  I don't know the Win7 purposes you have, but hopefully it all works out.

Thanks for that. I have now successfully installed the 64-bit Windows 7 on the 790, with BIOS set to UEFI, using the USB stick created by the Dell OS Recovery Tool for the Service Tag of the 7010. This one does show the USB as a UEFI boot option, which the 32-bit download didn't. The installation did not ask for a key (so presumably the machine has SLP key), and the Windows shows as activated. Now just to update!

I'm using the Optiplex 7010 as a Linux machine, and aim to keep it that way, but out of interest I will fit a spare HDD and install the Win 7, and assuming it ends up activated, I will see how hard it is to upgrade to Windows 10. As I mentioned earlier, the OS sticker on this one says Windows 8 Professional, but the only option in the Recovery Tool was Win 7 Pro, which seems to be the latest OS option in the original specifications. Possibly it was upgraded before sale.

"Now just to update!"  There won't be any updates from Microsoft for Win7.  It's been EOL since Jan. 2021 if I remember right.

Win10 isn't hard to update, but it updates slow.  I often do other things while it's updating.