msvcr71.dll
This file is not a system component: microsoft visual c++ 2003, long out of support. Restore it from the source that installed it rather than downloading a replacement.
Do not download this DLL on its own
Searching for a missing DLL by name leads to sites that hand you that single file. It is one of the oldest and most effective malware delivery methods there is, and a system DLL from an unknown source is indistinguishable from a deliberately modified one. There is never a legitimate reason to obtain a runtime component that way.
What it is
The C runtime from Visual Studio .NET 2003. Microsoft never shipped a standalone redistributable for it in the way it did for later versions, and support ended many years ago.
Where you see it: Software from the mid 2000s, and old Java applications that bundled it.
The correct fix is to reinstall the program that needs it, because applications of that era were supposed to ship this file in their own folder. There is no current Microsoft package to install. This file is one of the most heavily offered on DLL download sites precisely because there is no legitimate source, which makes it a particularly bad one to go looking for.
Why there is nothing to download here
There is no verified download we can offer for this one, because installing a file is not the fix. The steps above are what actually resolves it. That distinction matters: the sites ranking for this file name are selling a download that would not have helped even if it were safe.