You're here because you have a file that has a file extension ending in .an1. Files with the file extension .an1 can only be launched by certain applications. It's possible that .an1 files are data files rather than documents or media, which means they're not meant to be viewed at all.

Files with the AN1 extension are also called Street Atlas USA draw files, and these AN1 files are used by the Street Atlas USA application as reference data when a user views an associated project output file also created using this application. These AN1 files can also be created and entered or associated into a project output file with the Street Atlas USA software. This application creates these AN1 files each time a user enters graphical details associated to a project output file. When the project output file is viewed by a user of the Street Atlas USA program, this application locates the associated .an1 files and references the data stored in those AN1 files, such as map routes entered by the author of the project output file among other geographical details. The Street Atlas USA software is a GPS navigation application developed by deLorme to provide users with a convenient means of generating map files. Files classified as data files refer to data stored in files which needs to be referenced, loaded or used by an associated application. This happens when a user of an application opens and views the content of the data file or an associated output file that correspond to other data files. The AN1 format is used for this purpose, and files appended with the .an1 extension are classified as data files.

Launch a .an1 file, or any other file on your PC, by double-clicking it. If your file associations are set up correctly, the application that's meant to open your .an1 file will open it. It's possible you may need to download or purchase the correct application. It's also possible that you have the correct application on your PC, but .an1 files aren't yet associated with it. In this case, when you try to open a .an1 file, you can tell Windows which application is the correct one for that file. From then on, opening a  .an1 file will open the correct application. Click here to fix .an1 file association errors

Be careful not to rename the extension on .an1 files, or any other files. This will not change the file type. Only special conversion software can change a file from one file type to another.

A file extension is the set of three or four characters at the end of a filename; in this case, .an1. File extensions tell you what type of file it is, and tell Windows what programs can open it. Windows often associates a default program to each file extension, so that when you double-click the file, the program launches automatically. When that program is no longer on your PC, you can sometimes get an error when you try to open the associated file.