The extension COM identifies a command file, ie a executable file under MS-DOS.
Although these files resemble exe files, they do not contain metadata and use a simpler syntax. They are formatted in the DOS-COM (Common Object Module), which loads a series of raw data to predefined locations. Often, these files are used to execute a series of commands. The COM extension tells the system that the file should be processed by the command interpreter command.Com.
Note: If a directory contains files of the same name, each with the extension COM, and exe has the COM file priority. So if a file is started without specifying the extension via the command line, the COM file is executed.
A special application of a COM file is the EICAR test. This test uses a file with fixed content, the string X5O! P% @ AP [4PZX54 (P ^) 7CC) 7} $ EICAR-STANDARD ANTIVIRUS TEST FILE! $ H + H * to test antivirus programs without one to use real malware.
Most often resolving problems with opening COM files is very simple. Just install an appropriate program that supports such files. All of the listed programs support COM files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of COM files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate COM files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Parallels Desktop applications is not on the list, select "Browse" option in order to manually locate the directory where Parallels Desktop has been installed.
Sometimes problems with opening COM files may not lie with the application itself, but can arise due to other causes, such as: