How do I update my PSP?

I have a PS3 and I do not have Wi-Fi, so I use a 25 foot long ethernet cord to my computer. So I downloaded a bunch of demos from the PSN store an when I transfered them so my PSP and tried to play them it said I needed version 3.80 or better to play them and I only have version 3.51, I do not have and online instruction manuels so I don't know any update methods other than buying a game with this verson, HELP ME OUT HERE!

You could go to sony.com on your computer, then download firmware 4.01. Then connect your PSP using a USB, go into your PSP folder, create a GAME folder , then inside it make an UPDATE folder.

Copy the firmware download into your update folder, and it should be on your PSP. For it to update correctly your PSP battery has to be fully charged, and you have to have the charger connected while updating. Follow all the instructions and do not remove anything or turn PSP off or you risk bricking your PSP.

Wait until the update is complete, then make sure its updated, then you can remove the charger.

These instructions are also on the sony website under the firmware download.

don't take off your psp while updating or take out the MS. make sure your battery is alteast 70% so you can update and this is because it won't die during update.

WARNING: If turn off the power during the psp update your psp WILL not boot up.

Can I use the USB that comes with the PS3?RTCgator

I think the type that plugs into the PSP is called mini b, so if that came with your PS3, then sure. Try and fit it into the PSP.