SAN FRANCISCO (AP) — Microsoft has temporarily stopped fixing a serious security flaw on personal computers powered by certain chips from Advanced Micro Devices because the repair is crippling the affected machines.

The suspension will delay efforts to protect the AMD machines from potential intrusions caused by security bugs known as "Spectre" and "Meltdown." The problem primarily threatens devices running on processors from AMD's larger rival, Intel, but also could cause trouble on devices running on other chips.

Microsoft began offering updates to its Windows operating system to address the...