Since Visual Studio 2005 is "End of Life," the links are sometimes hidden. The safest way to find the official file is to search for the Microsoft Knowledge Base article KB2538242 .
This file is a critical system component required to run many older Windows applications developed using Visual C++. vcredist_x86_2005_sp1_x86.exe file download
If you already have the file and want to ensure it is legitimate and not a virus, check the SHA1 hash. A common legitimate version of this file has the following attributes: Since Visual Studio 2005 is "End of Life,"