Is there any good reason why I have ten versions of MS C++ on my computer?

While browsing my programs looking for things I don’t use so I can delete them, I saw that I had 10 different versions of C++ installed. There are 2 versions labeled “2005 Redistributable” (different sizes so I presume not identical), 7 versions of 2008 Redistributable (with various numbers), and 1 of 2010 Redistributable.

I never intentionally installed any of them, and I’m not a programmer so I have no personal use for them. My concern about not simply deleting them all is that some of my other programs may use the various specific versions for mysterious purposes not obvious to me.

So, can I delete all of them? All but the newest? Or leave them all?

Those are the redistributable shared libraries that were/are used by different programs you installed, which were compiled with various incarnations of the MS C++ compiler. Unless you’re absolutely certain some of them are no longer in use, you should keep them. Personally, I wouldn’t delete one even if I thought I was certain it wasn’t needed. They pose little risk, take just a bit of disk space, and anything you delete, you’re likely to have to re-install later anyway.

To put it another way, they are standard sets of functions and utilities that various programs you use depend on. Like for instance there might be a function to determine how much disk space there is, or create a temporary file. That way everybody doesn’t have to write code to do those same basic functions.

Different programs are compiled to depend on different versions of the libraries, I wouldn’t delete any of them if you want all your programs to run.

In other words, those aren’t “versions of C++” - they’re versions of the C++ Run-Time Environment (RTE). You might find a number of RTEs for other languages installed as well.