"Old" Software slower on Windows 10? [closed]

in our company we still have a "dinosaur" when it comes down to software: Word 95

It is running fine with Windows 10 (64bit), but can't be replaced easily, cause it has been stuffed with Macros for 25 Years now.

Word 95 only runs on one core, hence all the modern 12-20 core cpus don't offer anything.

But we noted, that - on two equal hardware-configurations - The very same "job" is significantly slower on Windows 10 than it used to be on Windows 7. (30s vs. 5 Minutes)

It's a macro generating documents, reading various other documents, putting them together, doing lookups in txt/csv files etc...

Do you have any Idea what might cause this difference in performance? All Major applications generally run faster with Windows 10, compared to Windows 7.

Solution 1:

I think a lot of emulation and backward compatibility tricks are done by the OS to get such an ancient application to even run at all on Windows 10 x64; that would be more than enough to slow it down to a crawl.