You can use FonePaw Video Converters Ultimate to convert 3gp videos to any format you like.
You can also use Any Video Convertor, video.online-convert.com, Free 3GP Video Convertor by DVDVideoSoft, and more.
convert it to avi format
Keepvid allows a person to save in three different formats. Those formats are MP4, 3GP or FLV.
The most common video file formats supported by smartphones, including the popular 3gp format, are MP4, AVI, and MOV.
vuclip.com
video converter is a good choice for you , it can help you to convert wmc to 3gp easily.
The 3GP Media Player allows videos and other video formats to be played on a 3G mobile phone. It plays 3GP, 3G2, MP4, MPEG, MOV, AVI, WMV, and RM formats.
I always use wondershare video converter ultimate. It's powerful that can convert videos to any formats, such as AVI, VOB,WMV, MP4, MKV, FLV, 3GP, MPG--even convert video to 3D. You can try it!
The best video format for Macintosh is .MP4,but .AVI or .3GP are also supported by it.
If you're sure it is 3gp to exe, then it is most likely a virus. 3gp is a video, and exe is an executable.
Search a normal flv converter or a video converter ultimate It supports convert FLV file to popular video formats including AVI, MPEG, WMV, DivX, Xvid, ASF, 3GP, MP4, iPod, PSP, Zune and convert FLV to audio formats MP3, WMA and WAV.
Pavtube Video Converter Ultaimte is an all-in-one video converter software to convert 3GP video files for Blackberry,Smart Phone,PPC.
it can support 3gp and mp4 but in mp4 you should adjust video rate ,audio rate.In both formats you should adjust screen size.