There are lots of tweaking applications available for Windows 7 and Vista. AeroTweak is another simple freeware tool which provides you with 50 tweaks for Windows 7 and Windows Vista. The application allows you to change about 50 different system parameters that affect user interface, performance and system security. Program does not require installation and consists of one executable file with 1 MB size, that is really useful if you will use it from removable device.
The tweaks are categorized into Windows Explorer, Performance and security tweaks. You can always restore the defaults using the button available on the right hand side.
It also provides system information including the product keys of Windows.