The registry is updated and a new entry is added to the file whenever you make any changes to the system through the control panel.
Whether you add or remove a hardware component, install or uninstall a program, open a new user account everything is logged in to the registry.
Therefore, it is quite obvious that as you keep using the computer more and more entries are generating in the registry making the size of the file huge. This is when the registry starts to function irrationally and the system becomes slower and prone to frequent errors. |