In general, you should find that many computers newer than 2005 can reliably run Windows 10 as a desktop operating system and should be upgraded to extend its life well into 2025. Windows 7 should be supported only into 2020.
That there is a good chance that many old PCs will keep functioning past 2020. As the deadline for the Windows 10 free upgrade date of July 29 approaches, it is a good time to re-evaluate old PCs to see if they can run Windows 10. These old clunkers can still be put to good use.
Windows 10 has these basic requirements, which isn’t much much more than Windows Vista other than RAM at a glance:
- Processor: 1 gigahertz (GHz) or faster processor or SoC
- RAM: 1 gigabyte (GB) for 32-bit or 2 GB for 64-bit
- Hard disk space: 16 GB for 32-bit OS 20 GB for 64-bit OS
- Graphics card: DirectX 9 or later with WDDM 1.0 driver
- Display: 800×600
However there are actually more requirements on the processor than what is listed above. The processor additionally needs to support CPU extensions PAE, NX, SSE2. Some processors can run 32-bit but not 64-bit Windows 10, because 64-bit Windows requires CMPXCHG16b, PrefetchW, and LAHF/SAHF extensions. Without going into details, it means that you can’t just rely on referencing the clock speed of the processor as per the above.
The oldest PC processors which can run 32-bit Windows include select processors of these families, and anything earlier will not work:
- later variants of Intel Prescott (also known as Pentium 4, Pentium D)
- later variants of Intel Dothan (also known as Pentium M, Celeron M)
- AMD ClawHammer/Newcastle (also known as Athlon 64)
- AMD Paris/Palermo (also known as Sempron, Sempron 64)
As for processors that cannot support 64-bit Windows 10 even though they can run 32-bit Windows, you should find success with newer Intel Core 2/AMD Sempron 64/AMD Athlon 64 processors, but limited success with Intel Pentium 4 and Pentium D processors with 64-bit support. Here is a blurb on Wikipedia explaining this mess which I will not copy here.
Here are my recommended minimum requirements for a decent Windows 10 experience:
- RAM: 2 GB (32 bit) or 4 GB (64 bit)
- Hard drive: 5400 rpm drive or faster
- Graphics for video playback at 720p30: video chipset or dedicated card supporting accelerated H264 video decoding (see also my article here) OR processor has a Passmark CPU benchmark score of over 1400
- Processor: Passmark CPU benchmark score of over 750
Sample Working Configurations
- Intel Core2Duo 2 physical cores @ 2.2 GHz, 4 GB RAM, Intel GMA 4500MHD
Acceptable, some lag spikes especially with multiple applications open, stumbles with higher bit-rate video but can play most videos at 720p30
- Intel Core2Duo 2 physical cores @ 1.2 GHz, 4 GB RAM, Intel GMA x4500
- AMD Athlon X2 3600+ 2 physical cores @ 1.9 GHz, 4 GB RAM, Geforce 9500GS
Close to unacceptable, random lag spikes even with single application open, can handle 720p30
- Intel Pentium 4 HT 1 physical core @ 3 GHz, 2 GB RAM, Nvidia Quadro 3450 (similar to Geforce 6800 LE)
Unacceptable, cannot handle online video
- Intel Core2Duo 2 physical cores @ 1.3 GHz, 2 GB RAM, Intel GMA x3100, 4200rpm hard drive
How to Look Up Processor Details
CPU-Z is an easy way to identify the processor: http://www.cpuid.com/softwares/cpu-z.html
From there you can find the code-name of your processor, the stepping, and the features it supports.
Windows 10 64-bit Requirements – http://superuser.com/questions/931742/windows-10-64-bit-requirements-does-my-cpu-support-cmpxchg16b-prefetchw-and-la/941175
Windows Lifecycle – http://windows.microsoft.com/en-ca/windows/lifecycle