Understand which kinds of old-computer slowness an SSD can improve, which CPU, RAM, graphics, thermal, or hardware limits remain, and when SSD plus Linux may extend the useful life of otherwise sound hardware.
Assess possible SSD failure using recurring read or write errors, disappearing storage, unexpected read-only behavior, corruption, freezes, SMART or NVMe health information, and connection or enclosure checks.
Decide whether an HDD-to-SSD upgrade is worthwhile by checking what currently feels slow, storage compatibility, RAM and processor limits, hardware condition, operating-system support, and the computer's remaining useful life.