installing app in android tab

hi friends i just download APK file from i copied that to my external sd card now my tab not show this file how can i install it plz tell me …
Answer #1
tick unknown sources from your settings, locate the APK, click it and install.
Answer #2
How To Install Games on Android Devices:
http://forum.mobilism.org/viewtopic.php?f=408&t=86556
That’s a small guide for installing games..But same thing apply to Apps…
Answer #3
you need to enable unknown sources, then you can use a apk installer program thats what i do.