My psp version 4.05 cannot play games.

No, to play a game you do not need to have a memory stick inside the PSP. However, you will need one to save you place in a game or download games.

There is also a version of the PSP that has 16 gigs of internal memory.

Let me know in the comments if you have any questions

you'd first have to downgrade your psp. try to lower it to 3.50 or 4. something. then insert the .pbp file... this file is a hack.. or an upgrader for a psp.. once you do this.. your psp will be back to version 5.03 but now you can play downloadable games.

Hi,

Follow the directive below to;

Step 1. Put on your PSP and use the arrow keys to go to "Saved Data Utility". Scroll down to "Memory Stick" and press the O button to get into the games stored in your memory stick.

This would enable you play your games on your memory stick, but if you are still not able to do that then get a UMD to play games or verify the version of your PSP.

You can only play the games in the memory stick after the PSP has been hacked.

Regards

HELLO! There's no need to downgrade ur PSP. If u have upgraded ur PSP from the official site and a official firmware has been installed on to ur PSP, it won't execute games(ISO,CSO) from ur memory stick. It will only run games from the UMD. If u want to run ur games from a memory stick u have to install a CUSTOM FIRMWARE. Try www.psp-hacks.com these guys have many softwares on their site. Dont worry its not that hard to put a Custom firmware onto ur PSP. 

u need to find a MP4 game and put it into e folder tt said MP4.. but is hard to find those game.. if u find some.. pls let me noe.. thanks..

IF YOU WANT TO THE OLD VERSION BACK AND PLAY AGAIN...... HOLD THE SWITCH UPWARD AT THE SAME TIME HOLD THE L AND R BUTTON AFTER THAT THE M33 RECOVERY MENU APPEAR... IF YOU HAVE SOME QUESTION JUST EMAIL AT [email protected]

Earlier you have said that you were able to play games from memory stick and since you updated your psp firmware the didn't worked.
First Check your current firmware version . To do this go to
Settings > System Settings > System Information on your PSP . If you your version showing  for example 5.00 M33 you are still in Custom firmware. In this case you should able to play the games from memory stick. or else you memory stick is back... or you custom settings are wrong.

If its showing  for example 5.00 you are with Sony's official firmware. In this case you wont be able to play the games from  memory stick. From here to make your PSP play the games from memory stick you need to Downgrade your PSP. Only way to make this possible is through Pandora Battery and Magic Memory Stick.
So please check your version and let me know so i can guide you further. Also tell me whether your PSP is PHAT or SLIM & LITE..... or check the version of your PSP by removing the battery. Underneth it find some letters and numbers PSP-100x / PSP-200x / PSP-300x

Hi Aneeshameeda

I think the best solution is to downgrade your PSP system software to the original version and check if your games load. What might have happened is that the firmware software that was on the PSP was downgraded to play copied games, and now you've changed the firmware to a newer version and that is why your games won't load. You might hac=ve to get your PSP downgraded again to play the games from your memory card.

Hi kalfan

What happened was that when you downgraded your PSP to -play game from your memory stick, that version was loaded onto your PSP for a reason. What you did now is install the latest firmware and that disabled you from playing games from your memory stick. You might have to get your PSP downgraded again with the older firmware version.

U NEED TO GET AN NEW MEMORY STICK