The need for a disk doctor arises only when there happens some kind of problem related to low disc space in your PC like you fail to install some application as the low disc space is incapable to accommodate it in the system or you may not be able to run an application or software as the system disc cannot support the same with free space.
Despite uninstalling the printer driver from your Dell laptop your Operating system of Windows 10 still attempts to install it as it sees the existence of the associated software in the system as the uninstallation was not done legitimately. This problem can be solved with the removal of the driver with the help of disk doctor.
Your Windows XP Home Version computer may show that the selected files are deleted from the system but in reality they remain as it was before attempting for disc clean up.
The attempt made for Disc clean up on your Windows 7 computer removed many of the system files needed to support different applications which run on the PC but the actual junk which was targeted to be removed is still there which can be only be eliminated with some good disk doctor.
Using the using the DISM command for Windows 7 SP1 PC of yours do not perform the cleanup of the image files stored in the system which can be only cleared if disk doctor software of repute can be utilized.
Windows 8.1 computer of yours takes 5 to 7 hours for conducting a disc clean up which is so annoying as this task can be performed within few seconds if right type of disk doctor is used.
The DLL Suite can be considered as one of the best disk doctor which does the cleaning up of PC disc in less than a minute and it results is regained pace with no hangs or application failures.