ST380815AS  is a VERY VERY OLD Drive. These units can be upgraded to 10 HOWEVER you can get a much better much faster unit like a 9020 Tower for almost the same price as the cost of the windows licence. There is a reason why drives have a 5 year max warranty. Updating to the latest bios will allow drives up to and including 2TB. [URL] This is not a hugely expensive drive. Windows 10 is not supported but will run fine on a 755. An OEM 10 DVD is the recommended install media. [URL] Once installed with the I dont have a key option for Home $109 or Pro $199 you can purchase a key from microsoft. The individual drivers are here [URL] The AMT HECI SOL drivers and Audio Drivers etc are VISTA 32 or 64 and will work with 10. There are no issues clean installing windows 10 on the 755.  There are specific Legacy Driver requirements.  Windows 10 works with Optiplex GX620, 745, 755, 760, 780, 960, 980, 990 etc. [URL]   I also have no issues with upgrade install from previous versions 1511 or 1607.   Clean install from Known good media is more stable however.   Bios should be updated to latest for best results.  That may require reinstall of XP temporarily to get up to A22.  You must update in stages you cant jump from A00 to A22 in 1 step. [URL]     [URL]   If you have windows 10 download and create a Windows 10 1703 DVD and burn at 1X or 2X or 4X max speed and clean install.   Most of the hardware works out of the box but the chipset and intel RST and video cards like the Radeon 2400, 2600, 3400, 4600, etc are also legacy.   The AMD auto detect utility does not work with these legacy cards and the Audio Codec is not installed automatically. Directx June 2010 is a must. [URL] You download the file, extract into a folder, and run DXsetup.exe as administrator. This is why you can now buy these models with Windows 10 Preinstalled.  OEM System Builder DVD versions of the software in 32 and 64 bit ARE available.  You need at least Pentium D 900 series like the 915 or better in order to install 64 bit windows 8.1 or 10. Pentium D 800 series works fine with 32 bit version of windows 10. [URL] I tell my clients these are Free computers because the retail cost of windows home is $119 and PRO is FQC-08788 $199.  I only recommend the TOWER version because they do not have proprietary power supplies and they are the most upgrade-able. [URL]                
Hello, Previously, there was a low battery voltage error, and I replaced it. The error is gone now but it won't boot to my Windows Vista. Please help.   Best regards.
Optiplex 755 - No errors or diagnostics lights but won't boot