Sometimes, slow PC performance is attributable to malware. Other times, it’s due to more mundane reasons like a slow hard disk drive (HDD) or solid-state drive (SSD). To avoid the latter issue, schedule defragmentation if your PC uses a HDD (the operating system will know this automatically). For SSDs, the equivalent maintenance operation is called TRIM and is usually enabled by default, unless you are using a very outdated operating system, in which case you should upgrade it.