Dell Hardware release date and Windows 8.1 support

Get the info you want from Microsoft. The operating system is supported by MS, not Dell. Use the Windows Upgrade Assistant to test any computer--

windows.microsoft.com/.../upgrade-assistant-download-online-faq

And if you want to know specifically if Dell supports Win 8.1 on a system, look at the Drives/Download page for the model and see if Win 8.1 drivers are offered.

Note: Even if Dell doesn't offer drivers for Win 8.1 for a PC model, that doesn't mean Win 8.1 won't work, though you may have to hunt a little for some drivers. The upgrade assistant Mary linked should help identify possible problems.

I'm running a Win 10 beta release on this Dell laptop and when I look at the drivers page for this model, it shows a message saying Dell doesn't support Win 10 on this model. But Win 10 is working ok, aside from the bugs that Microsoft -hopefully- fixes before the official release at end of July. 

 Win 8.1 pro ran fine on a Latitude D620, with whatever nVidia card is in it.

It ran Dell QuickSet stuff without issues as well as the non-Dell / non-supported SpeedFan plugin.

Some of the drivers were "Vista" drivers and I found references that these worked OK on Win7 and Win8.

I used this system with a D-Dock docking station but didn't test all the ports and all the input/output and I didn't install drivers or test items like Modem's, floppy disk etc.

Release date has nothing whatsoever to do with working with 64 bit windows 8.1 or even 10.

Dell supports the OS they came with period end.  They do not "support" upgrades of the os and provide drivers for higher OS than came with the unit.  All of the machines in the strange list will work with vista, windows 7, windows 8, windows 10.  The 780, 755, 745 330 came with vista or windows 7 being from 2010, 2009 or earlier.

The GX520 is from 2006.

If they came with VISTA or better then 8 or 10 will work.

The GX520 is not worth upgrading due to it having 2 ram slots and the X16 video slot removed.

HOWEVER if you put a pentium D 915 in a GX520 and update the bios to A11 it will run windows7, 8.1 or 10. Its going to be very very very very very very very very very very very very slow but it will run.

The other Optiplexes can be upgraded with X16 based Radeon HD6450 and will run windows 7 or 8 or 10 just fine.  The RAM in them on the other hand will be expensive.  The cost of upgrading to 8 gigs of DDR2 for some of them would not be cost effective because newer systems Like the Precision T3500 that support DDR3 are available for less than the cost of the Ram Alone on the other Optiplexes.  The precision Line also can take full size video cards whereas the optiplexes are limited to low end cards.

None of these systems have native Dell driver support for Windows 8.1/10 64 Bit however Windows 10 64 Bit will work either natively or with Windows 7 64 Bit drivers.

I advise holding off the mass upgrade until the end of the month and instead directly clean install all systems with Windows 10 opposed to Windows 8.1.

Windows 7 Systems

• Latitude E4200 (Late 2008) → Use Windows 7 Drivers
• Latitude E4300 (Late 2008) → Use Windows 7 Drivers
• Latitude E5400 (Mid 2008) → Use Windows 7 Drivers
• Latitude E6220 (Mid 2011) → Use Windows 7 Drivers

• OptiPlex 760 (Late 2008) → Use Windows 7 Drivers
• OptiPlex 780 (Late 2009) → Use Windows 7 Drivers

Windows Vista Systems and Unofficial Driver Sets

• Latitude D430 – Windows 7 32 bit (Mid 2007)
• Latitude D530 – Windows 7 and 8.1 64 Bit (Early 2008)
• Latitude D530 – Windows 7 and 8.1 32 Bit (Early 2008)
• Latitude D531 – Windows 7 and 8.1 64 Bit (Mid 2007)
• Latitude D531 – Windows 7 and 8.1 32 bit (Mid 2007)
• Latitude D630 & D630ATG & D630XFR – Windows 7 and 8.1 64 bit (Mid 2007)
• Latitude D630 & D630ATG & D630XFR – Windows 7 and 8.1 32 bit (Mid 2007)
• Latitude D631 – Windows 7 and 8.1 64 bit (Early 2009)
• Latitude D631 – Windows 7 and 8.1 32 bit (Early 2009)
• Latitude D830 – Windows 7 and 8.1 64 Bit (Early 2007)
• Latitude D830 – Windows 7 and 8.1 32 bit (Early 2007)
• Latitude D420 – Windows 7 32 bit (Early 2006)
• Latitude D520 – Windows 7 and 8.1 32 bit (Early 2006)
• Latitude D620 & D620 ATG – Windows 7 and 8.1 64 bit (Early 2006)*
• Latitude D620 & D620 ATG – Windows 7 and 8.1 32 Bit (Early 2006)
• Latitude D820 – Windows 7  and 8.1 64 Bit (Early 2006)*
• Latitude D820 – Windows 7  and 8.1 32 Bit (Early 2006)

* 64 Bit compatibility depends on the processor installed.

• OptiPlex 330 – Windows 7 and 8.1 64 Bit (Late 2007)
• OptiPlex 330 – Windows 7 and 8.1 32 Bit (Late 2007)
• OptiPlex 740 – Windows 7 and 8.1 64 Bit (Late 2006)
• OptiPlex 740 – Windows 7 and 8.1 32 Bit (Late 2006)
• OptiPlex 745 – Windows 7 and 8.1 64 Bit (Late 2006)
• OptiPlex 745 – Windows 7 and 8.1 32 Bit (Late 2006)
• OptiPlex 755 – Windows 7 and 8.1 64 Bit (Mid 2007)
• Optiplex 755 – Windows 7 and 8.1 32 Bit (Mid 2007)

Windows XP Systems

• OptiPlex GX520 (Mid 2005)**

** processor incompatible with 64 Bit Edition of Windows 8.1/10. It will work with the 32 Bit Edition only.