I've seen this question asked too many times, and it's only going to get asked again, so to make it easier on all of us I decided to make this quick little guide.

First thing you'll want to do is to enter recovery mode on your PSP. If you don't know how to get there, I don't think you should be wandering around in this directory just yet, it's too dangerous if you mess up.

Go to: Advanced>Toggle flash(0)

Then, on your computer browse to your PSP's directory letter. Mine is "G:\"


Click Tools>Folder Options.
If you're on Vista, you may need to hold the "Alt" key to display the Menu bar.


In Folder Options, click the "View" tab. Select the "Show hidden files and folders" radio button.


Now uncheck the "Hide protected operating system files" check box.


A little alert window will pop-up, just click yes.


After that, select "OK" and this should be your result. You should now be able to see all of the files and folders in your flash(0) directory.

When you're all done in flash(0), you can go back and undo the above steps to re-hide hidden and system folders.