Consider using Arm Compiler for Embedded (AC6) (free up to a code size limit) or GCC (GNU Arm Embedded Toolchain) , as Arm no longer provides Compiler 5 free of charge.
Update 7 is often bundled with specific versions of Keil MDK (typically 5.30 through 5.36). If it is missing, it can be downloaded as a standalone "Legacy Compiler" pack from the Keil website. arm compiler 5.06 update 7 download