This file is a part of Th cUR library. Was developed by cURL, http://curl.haxx.se/.
This is a system file, or, possibly, hidden. It is usually located in %System% folder and its size is 236 Kb.
What options do you have to get rid of "libcurl.dll download microsoft" issue.
In the majority of cases, the solution of libcurl.dll download microsoft issue is to correctly reinstall particular software that is using this file on your PC, to the Windows system folder, or to the game or application installation folder.
But in case you do not have the installation distributive of application or just do not know, what program is using this file – you should probably download this missing or damaged file and put it in the right folder.