Best tool to perform multiple renames under windows?

Possible Duplicate:
How can I mass rename files from the command line or using a 3rd party tool?

Requirements:

• works for files/folders same time


• works on WinXP, Win7 (EDIT: 32 and 64 bit versions)


• supports regex


• has right click shell integration (I can select several files in folder and right click to rename only selected files in program)

Preferences:

• freeware


• no Commercials