Once I found an interesting quote like “The most suitable stuff of our life always comes free”.Such gp4 file format comes under uncommon files category or misc category.

gp4 File Description
It is a fax document having no brand name which is stored in the CCITT (International Telegraph and Telephone Consultative Committee) standardized form. This gp4 file format is identified and accessed by some Windows fax programs such as SFaxTools Batch Fax to PDF, SFaxTools Studio FaxSee Pro, Magic View & Converter, SFaxTools Batch Fax2JPEG and so on. It does not support multi platform or environment.

Guitar Pro 4:
The file extension gp4 stands for Guitar Pro 4, which comes under the banner of uncategorized miscellaneous format. It supports multi platforms like Windows, Linux, Mac OS, and so on. Here the Guitar compositions are stored in the music notations which are accessible only by some guitar programs. As we know well the computer’s registry is nothing but a computer database. Generally the performance of your computer depends upon the registry. If your data got badly defragmented in your registry then your system starts inching towards the throughput. There are many software and free registry scan websites to cure this problem. Just use one of them to optimize your system performance.