MSDOS Applications

I have a DOS based program that was written back in the old 286/386 days that run control systems. Upgrading is not an option. The program is written for a maximum processor speed of 25 mhz (Yea I know). Is there any way to use a Pentium II 133 mhz computer configured for DOS and slow the processor down. my computers are obviously very old and are beginning to die on me and I need a solution.