This type of software combines some or all of the below functionalities:
- Registry cleaner
- Driver Updater
- Temp file cleaner
- Disk optimizer (disk defragmenter)
- Report system errors
Since all these functionalities are offered by free tools built into the Windows operating system, many system optimizers are considered Potentially Unwanted Programs (PUPs), especially if they exaggerate the seriousness of possible improvements that can be made on user system.