OK. Go to the icon that looks like a suitcase on the browser screen and go down to system settings menu, go down to system information and take a look. The chances are you have firmware 1.52 or above. You will be able to upgrade to firmware 2.00 using the umd disc that came with the PSP.
Once you are upgraded go and find MPHDowngrader (try google or have a look
HERE!!! ). You will also need to find the PSP Firmware 1.5 dump, again google will assist.
Simply follow the instructions that come with MPHDowngrader to downgrade to firmware 1.50.
This firmware will allow you to run homebrew applications as well as backups of UMDs THAT YOU ALREADY OWN from your mem card.
This proceedure is carried out at your own risk.