Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

mclmcrrt77.dll missing after installing Windows 7?

Asked by Cathy on 9 Jun 2011

After OS upgrade to Windows 7 from XP, my .exe stopped working. The error message says: "The program can't start because mclmcrrt77.dll is missing from your computer. Try reinstalling the program to fix this progblem."

I tried to rerun MCRInstall.exe but it didn't help. (MCR v7.7)

Please help~




No products are associated with this question.

2 Answers

Answer by Walter Roberson on 9 Jun 2011

Possibly a PATH problem. See this solution

Question: did you go from 32 bit to 64 bit? If so then you will need a different MCR, I believe.


Cathy on 9 Jun 2011

I think this might be the exact problem! I found I am upgraded to 64 bit. Do you know where to download the 64-bit MCR? thanks a lot!!

Kaustubha Govind on 10 Jun 2011

You will need to have the person who compiled the application to provide you with the 64-bit version of the MCR (it is included with a 64-bit installation of MATLAB Compiler). The MCR cannot be placed for public download for licensing reasons.

However, note that users have been able to have 32-bit MCR running on 64-bit Windows in the past - see

I think the real reason in your case is that $mcr_root\ver\runtime\win32 has not been added to your system path. I find that on Windows 7, if you don't run installers as Administrator, it doesn't not give them privileges to perform operations like modifying the system path.

Walter Roberson
Answer by Cathy on 15 Jun 2011

Yes the 32-bit MCR works on 64-bit Windows. The trick is just to restart the computer after the installation. Thanks to all! :)



Contact us