C:\Program Files\Microsoft Dynamics AX\60\Server\bin
1. Open command prompt as an administrator
2. Go to AxBuild path C:\Program Files\Microsoft Dynamics AX\60\Server\bin
3. Run below command.
AxBuild.exe xppcompileall /aos=<AOS instance number> /altbin="C:\Program Files (x86)\Microsoft Dynamics AX\6.0\Client\Bin"