Optiplex 755, cannot install Windows 8, 8.1, or 10

Ali_k,

Unfortunately, Windows 10 is not supported on the OptiPlex 755 by Dell.

Before Updating you should download Bios and UNINSTALL any Antivirus Software.  Windows 7 8 and 10 work fine on this model.  HOWEVER you need AT LEAST a Pentium D 915 dual core cpu in order to run 64 bit versions.  NX  aka Execute Disable Bit must also be enabled in bios. Its under security.  Clean install of 7 or 8 or 10 works fine.  There will never be 8 or 10 drivers so you must use the 32 bit or 64 bit versions of the drivers as appropriate for your OS version.   Vista/7 drivers work under 8 and 10.   The main unrecognized hardware is as follows.

http://downloads.dell.com/published/pages/optiplex-755.html

Description	Supported OS	Download
Intel G31/G33/Q33/Q35 Graphics Controller, v.8.15.10.1867, A02 This package provides driver for Intel G31/G33/Q33/Q35 Graphics Controller and is supported on OptiPlex 330/360/755 running the following Operating Systems: Windows 7.More details	Windows 7 64-bit
Intel G31/G33/Q33/Q35 Graphics Controller, v.8.15.10.1867, A02 A-rev Win7 32-bit driver for Bearlake 15.12.75.2 driver 1867, all languagesMore details	Windows 7 32-bit

Description	Supported OS	Download
Dell WinPE Driver CAB Pack This package provides Dell WinPE Driver CAB Pack and is supported on OptiPlex, Tablet, Precision, XPS Notebook and Latitude models that are running the following Windows Operating Systems: XP, Vista, Windows 7 and Windows 8.More details	Windows 8 64-bit Windows Vista 32-bit Windows Vista 64-bit Windows XP x64 Windows XP Windows 7 32-bit Windows 7 64-bit Windows 8 32-bit

Description	Supported OS	Download
Intel Chipset Driver This package provides the driver for the Intel Chipset and is supported on OptiPlex, XPS Desktop, Precision, Latitude and Dimension models that are running the following Windows Operating Systems: XP and VISTA.More details	Windows Vista 32-bit Windows Vista 64-bit Windows XP Windows XP x64

Description	Version	Supported OS	Download
Analog Devices ADI 198x Integrated HD Audio, v.6.10.x.5491, A02 Analog Devices HD Audio driverMore details	6.10.x.5491	Windows Vista 64-bit Windows Vista 32-bit

Description	Supported OS	Download
Intel AMT SOL/ LMS, v.3.2.20.1049 PV, A02 This package provides Driver for Intel AMT SOL/ LMS and is supported on OptiPlex 755 running the following windows operating systems: Windows 7, XP, Vista.More details	Windows Vista 32-bit Windows 7 32-bit Windows XP Windows 7 64-bit Windows Vista 64-bit Windows XP x64
Intel AMT HECI, v.3.2.20.1049 PV, A02 This package provides Driver for Intel AMT HECI Chipset and is supported on OptiPlex 755 running the following windows operating systems: Windows 7, XP, Vista.More details	Windows 7 32-bit Windows XP Windows Vista 64-bit Windows 7 64-bit Windows Vista 32-bit Windows XP x64

Description	Version	Download
Dell Optiplex 755 System BIOS This package provides the BIOS Update for Dell OptiPlex 755 running the following Operating Systems: Windows and DOS.More details	A22
DELL,DSK PROG,BIOS,OPTI-755,,A21 OptiPlex 755 System BIOSMore details	A20
Dell OptiPlex 755 System BIOS, A19 This package provides the BIOS update for Dell Optiplex 755 running the following Operating Systems: Windows and DOS.More details	A19
Dell OptiPlex 755 System BIOS, A17 OptiPlex 755 System BIOSMore details	A17
Dell OptiPlex 755 System BIOS, A16 OptiPlex 755 System BIOSMore details	A16
Dell OptiPlex 755 System BIOS, A15 OptiPlex 755 System BIOSMore details	A15
Dell OptiPlex 755 System BIOS, A14 OptiPlex 755 System BIOSMore details	A14
Dell OptiPlex 755 System BIOS, A13 OptiPlex 755 System BIOSMore details	A13
Dell OptiPlex 755 System BIOS, A12 OptiPlex 755 System BIOSMore details	A12
Dell OptiPlex 755 System BIOS, A11 OptiPlex 755 System BIOSMore details	A11
Dell OptiPlex 755 System BIOS, A10 OptiPlex 755 System BIOSMore details	A10
Dell OptiPlex 755 System BIOS, A09 OptiPlex 755 System BIOSMore details	A09
Dell OptiPlex 755 System BIOS, A08 OptiPlex 755 System BIOSMore details	A08
Dell OptiPlex 755 System BIOS, A04 Dell OptiPlex 755 System BIOSMore details	A04
Dell OptiPlex 755 System BIOS, A03 Optiplex 755 BIOSMore details	A03
Dell OptiPlex 755 System BIOS, A01 Initial BIOS release.More details	A01

Hello, i am having trouble getting windows10 to install on this 755 optiplex with a core2duo e4600. The only execute disable i see in the bios seems to be "execute disable memory protection" and it is enabled. Yet i am still getting the NX error when i try to install win10.. Any idea if i am maybe missing the setting in the bios?

Never mind... it seems Disabling "execute disable" did the trick.. maybe the bios A22 has the switch backwards or maybe i just misunderstood..

EDIT: Install froze at 86% with error 0xC1900101 0x4000D  This happened twice and then i gave up. Luckily it was able to revert back to win7

Thanks for the helpful info here!

no case size stated, MT? W8 is not sold now,  so we can check that  off, right?

Fresh windows 10. is the only choice, W7 support ends Q1 -2020 so W7 is not viable now. end it  now.

I have W10-64b it running on old pentium 4 651 (newest stepping)

your E8500 is not old, as that and is fully trusted execute enabled. NX, VT(x) and LAHF, so is 64bit ready.

The Quad Core 2, is even newer and better. 

Dell sure does not support it, but that only means them. (there is no warranty  this old) so only you need support it.

Sure some DELL free APPS will fail so don't run those. (just run firefox or Edge Or Chrome)

It is no Gaming PC, of any kind so that be off the table.

I have no Idea at all what you use a PC for , nor what program apps you wish to use.?

At the worst case a new GPU card if you need faster 3D graphics.

e8500 CPU ,  sure upgrade BIOS sure,  so it can use all supported CPU and DDR ram.  never run old BIOS.

"or 10 it does not upgrade nor install a fresh copy. "(is this past tense, did not fresh load? or a question new  load)  forget upgrades, load w10, fresh, it sure WILL. (if that old old HDD is not bad as all are this old)

Did you first replace that dead COIN CELL RTC battery yet?

I can not speak for BIOS support, nobody can due to 2 many CPU that run here,  DELL never tests them all more like 3 tested, (or what they sold) The full list of Q35 is here, if you read this.

e8500 s-spec, SLB9K  steppings is  best. (on lid of CPU, best one)

My list is simple) (qalifications)

• Dell supports it,  NOT. (no is the word on most in the Q35 list, so forget Dell short list ,just TRY !)
• BIOS supports, (maybe if you upgrade BIOS it will) costs $0 (just do it, first)
• The Q35 supports vast CPU seen above, use only the newest core2 chips, and highest stepping codes.
• a newer CPU in QUAD core 2, is not expensive but is if you consider the MOBO is worth same $$$
• The MOBO may not clock fast enough for the newer CPU but all you really want for sure is w10-64bit.
• Even w10 32 bit is strict, and needs NX and LAHF  support on CPU die) yours does.
• The wattage  deal, not told by DELL, but avoid the 95watt CPU, is my guess,  or needs new Heatsink.?

Id retire this PC and buy a $50 used Dell 3020 MT (minitower) optiplex,  sure would.

the best DUO  is Core 2 Duo E8700  (stepping.SLB9e) pray LAHF is supported, intel deleted there datasheets !

but  , the waybackmachine solved this for me.

the best CPU for this PC is this generation,  (if bios does not go , upset)

What w10 needs: (as does VT)

quote
Support for LAHF and SAHF instructions appeared shortly after NX/XD was introduced. AMD introduced support for the instructions with their Athlon 64, Opteron and Turion 64 revision D processors in March 2005 and Intel introduced support for the instructions with the Pentium 4 G1 stepping in December 2005."

I tested this P4 and works here.

im in the wayback machine (intel.com) finding old LOST data sheets, wow slow but are all there,

now I can use this to see what steppings have what.  wow.

here we go back to year 2010.  see this list, what you want is VT-x support, note how steppings change this.

so  does your E8500 have vtx. step C0 best SLAPK

seems your are good.

here is what to do.

Erase the HDD first, (backup first, this is always what to do, always stay backed up your data and apps and licenses.)

then test the HDD with S.M.A..tests, (using linux demo disk or testing in 2nd PC with Crystaldiskinfo.exe (free)

OK HDD is still good , or buy SSD for $20 and be amazed at speeds.

now make sure the PC boots to USB<  turn on all USB ports in bios then make USB first in boot order

Take that USB stick just made by you with the windows USB builder for w10 (32/64b) Picked.

then boot the stick and load w10 fresh.  no better way works.

end story.

the NX , feature is not optional at all w10.,and must be enabled in BIOS.

turn on VTx too if seen there, a PC will have  list of Advanced CPU instructions, turn them all on.

most are off by default (the reason is complex but the answers is really simple, some CPU do not have those instructions. even older DIE steppings had no such thing) so is off on legacy PC.  to stop OS from trying to find them.

This post  is CORE 2 DUO, and there are lots of DUO's made,  and steppings, the  non E82xx,83,84,85,86) do not have the advanced features,  The data sheet states that near page 1. 

the E75xxx have no trusted execute features. (avoid them)

never post W10 questions  about installs. unless you tell what CPU you actually have.  (for sure this old, 2007 to 2007)

I have windows 10 pro 64 bits installed on my optiplex 755 and is work very fast and good.

There are Zero issues installing 10 on a 755 any size.

Its not supported but it does work.

nx ERROR means execute disable bit in security is set wrong

go into bios and however its set toggle the other way and re try install

I have a dell optiplex 755 with an e8400 processor