Do not use iconpackager or related softwares, this apps mess with Windows 7.
Here's some system files that IP may corrupt: imageres.dll, explorer.exe and others.
My Computer
Computer Manufacturer/Model Number
Desktop
OS
Windows 7 Ultimate x64
CPU
Intel Core i7 2600K
Motherboard
ASRock Fatal1ty P67 Professional
Memory
G.Skill RipJawsX 8GB (2x4GB) DDR3 PC3-12800
Graphics Card(s)
AMD/ATI XFX Radeon HD 6970
Screen Resolution
1920x1080
Hard Drives
WD Caviar Black 1TB
WD Caviar Blue 500GB
Crucial C300 64GB (SSD)
I use tuneup utilities to change icons, but it is not free. Though I dont have tried to change the live icons by it, it replaces system icons very well. here is how it works :