The Samsung Captivate, as well as several other AT&T phones, have a security block put in place by AT&T to stop users from installing apps from sources other than the Android Market. Unfortunately, since Google has banned Mango from the Android Market, that distribution method is no longer an option for Mango.
However, it's still not impossible to install non-Market apps onto these phones, and luckily the people over at AndroidCentral.com have made a neat little program that lets you install (sideload) non-Market apps even on AT&T phones, called the "Android Central Sideload Wonder Machine".
To start, download this program
: http://cdn.androidcentral.com/sites/and ... _Setup.exe
After you've downloaded it, double-click on the file to launch the installer.
Click the 'Next
' button a few times to accept the default settings and install the program.
Once the installation finishes, open your computer's Start menu and launch the "AC_SWM
Next, plug your phone into your computer. On your phone, go to the Settings
menu, tap on Applications
, tap Development
, and finally, check the box labeled USB Debugging
Now go back to your computer and click the Choose APK
button and find the Mango.apk
file you downloaded a little while ago (if you can't find it, just re-download it from http://mango.leetsoft.net/install-android.php
Once you've selected the Mango.apk file, make sure to check the box labeled Update existing app
(but only if you have a previous version of Mango installed, which I'm assuming you do). And finally, press Install
A black box will appear showing the installation progress. If no errors appear, you're done! Otherwise, let me know and I'll see what I can do.
Sorry for the inconvenience, I know this is a pain in the neck but sadly there's not much else I can do since Google keeps removing Mango from the Market. :/