5.50 GEN-D is the latest release of the GEN CFW. 5.50 GEN-D2 is the latest patch for it. Having 5.50 GEN-D2 installed on your PSP allows you to play games that require 5.55 upto 6.10 OFW without the need to upgrade!

If you want to install custom firmware on your PSP, read this guide on how to install custom firmware After installing custom firmware, you can update your PSP to the latest stable version, 5.50 GEN-D2

What do I get with Custom firmware 5.50 GEN-D2?

• All features of 5.50 GEN-A and 5.50 GEN-B2 are available.
• Compatibility with games requiring firmware 5.51 with no additional handling (no more Decrpyting PSP games)
• Compatibility with most of games normally protected and refusing to be ran on a Custom Firmware (Full Metal Alchemist, Soul Calibur, etc). Yoshihiro has created a system to run them and he succeed to make this system more stable and it’s now compatible with all PSP, unlike the 5.50 GEN-C.
• Possibility to connect at the Playstation Store via MEDIAGO, to retrieve game and goodies without having to install Fake USB or other complicated stuff.
• Support for 480×272 AVC video playback.

Fixes for Custom Firmware 5.50 GEN-D2:

• Evangelion Anti CFW patch Fix
• Fix Wlan TKIP in game loop : pes 2009 , fifa , motorstorm , GTA cw ect….
• Fix Video Output With 5.5X and 6.X Games like GTA Chinatowns War
• Fixed recovery menu with make Pandora and make battery normal
• removed splash screen http://www.pspgen.com but you have another spash screen in red color for let you know if the decrypter work .

So how do I install 5.50 GEN-D2?

Read this guide on how to install 5.50 GEN-D2 on your PSP.

[via How to install Custom Firmware on your PSP]