New Windows security patches and performance
All computers, regardless of Operating System, have been found to be affected by two major security bugs. Fixes for these bugs are coming, but may have a significant effect on your computer's performance, particularly on older Windows machines.
If you are still running an older version of Windows we strongly recommend that you upgrade to Windows 10, for reasons of both security and performance.
According to Microsoft:
“With Windows 10 on newer silicon (2016-era PCs with Skylake, Kabylake or newer CPU), benchmarks show single-digit slowdowns, but we don’t expect most users to notice a change because these percentages are reflected in milliseconds.
With Windows 10 on older silicon (2015-era PCs with Haswell or older CPU), some benchmarks show more significant slowdowns, and we expect that some users will notice a decrease in system performance.
With Windows 8 and Windows 7 on older silicon (2015-era PCs with Haswell or older CPU), we expect most users to notice a decrease in system performance.”