program no longer compatible

[Debra Felske]

I can no longer open my version of gnucash.  I'm running Windows 7 and gnu ver. 2.4.13.  Error msg: " The version of this file is not compatible with the version of Windows you're running.  Check your computer's system information to see whether you need an x86 (32-bit) or x64 (64-bit) version of the program, and then contact the software publisher."  It worked on Friday, why isn't it working today?

Deb