Ultimate Windows Tweaker (UWT) is the litest and simplest Windows tweaker which I have ever met. Just a few hundred KB is size (about 350KB) and does not need to be installed. A stand alone file just to run and tweak your Windows Vista and 7 does not capture a huge amount of your RAM. Best of all, it is Free.
There are lots of functions provided by Ultimate Windows Tweaker but the one which I liked is making your x86 Windows capable to recognize 4GB of RAM. By default, Windows Vista x86 n 7 x86 can not recognize RAM over 3.5GB.
The UWT has two pane window. Left pane contains module names and right pane contains the functions under that specific module. There are total 9 modules:
1: System Information: Contains the basic info of your computer like OS, release, RAM, etc.
2: Personalization: It has further 3 sub-modules of Explorer, Start Menu and Taskbar which contains 32 different functions in total.
3: User Accounts & UAC: Functions regarding User Account Control, Welcome Screen text n button effects, etc.
4: System Performance: Like waiting time to shutdown computer, to kill non-responding application, etc.
5: Security Settings: Let you create different types of restrictions like Admin restrictions, explorer and applications restrictions along with Windows update settings.
6: Network Tweaks: Tweaks related to networking like disabling Remote Desktop Sharing, hiding from network neighborhood, etc.
7: Internet Explorer: Different types of IE configurations.
8: Additional Tweaks: More tweaks.
9: About: Contains End-User Agreement.
Open the following URL to download UWT.