Good news is that the new Windows 7 Calculator works on Windows Vista too, if it’s been ported or migrated to Windows Vista.
Windows Vista users who want to use the more advanced Calculator program from Windows 7 can download the following RAR archive which consists of calc.exe with its mui language file extracted from Windows 7 pre-beta build 6801.
To Run Windows 7 Calculator :
1. Simply unpack the content to another folder
2. Run the calc.exe to use the Windows 7 Calculator in Windows Vista.
To replace existing default Calculator program in Windows Vista :
1. Copy calc.exe to \Windows\System32\, and calc.exe.mui (in en-US folder) to \Windows\System32\en-US\ folder
Overwriting existing file (you may want to backup the old Calculator binaries first in case of error running Windows 7 version). Voila, now the new Windows 7 Calculator has been installed on Windows Vista.
Download:
Windows-7-Calculator.rar from WinVistaClub.