APM file format is categorized as raster image files. The main purpose of these files is to scale the image file on the specific displaying device.
It is a wrapper file format of Windows meta file format. This file has a header command at beginning which tells about scaling and placement parameters. The header is of 22-byte. In order to use such files the user has to first strip the header file using a separate utility. These files are similar in structure as compared to WMF file with addition of a header part of 22-byte. These files also contain original image.
In addition to the problem described above, i.e. the lack of the appropriate application to support the .APM file, there may be several reasons that cause problems with opening and operation of the data format:
A quite common problem is the lack of application in the appropriate version. Even if you have an application, with the help of which you should open the .APM file, you may have a problem with it because of its version. Perhaps in previous versions the application has not yet supported the .APM file, so download the update and check again.
If you have already installed the appropriate application, and it is the correct version, the file may not open correctly, because the operating system does not have information that this program supports the file. So you need to "show" which program the computer should use. To do this:
It also happens that the file you want to open is corrupt and therefore there is no such possibility. In this situation, you should find its different version, or ask a person from whom you got, to send it again.