What George said ..... and if you have the files on any other storage media eg CD, DVD, Memory stick or external hard drive and they are not inserted/plugged in.
As a matter of courtesy please do not type in capitals - this is considered as shouting on forums.
I found the file by plugging in my exsternal device, but now I'm saving it to a differebt drive on my computer then trying to load it back into MEP, I still get that screen till I plug in my exsternal device in then the file loads, it doesn't make sence to me I saved it in a completely different drive,
Remember MEP does not actually hold the file, it simply points to it and keeps the edit data for that file. If you moved the file to a different drive, you are going to have to remove it from your time line and re-insert it from the new location and re-edit as necessary. Or you can try disconnecting the drive that it was originally on and when you get the lost file message, browse to the new locations and re-connect the file. I have not tried the latter approach but theoretically it should work.
This can sometimes be annoying but the fact that this approach is a totally non destructive approach actually saves you disc space in the long run.
If you have copied the files, and the project MVP file if it is also on the external drive, from your external hard drive to the internal drive on your computer using Windows Explorer make sure you disconnect the external drive before starting MEP.
Start MEP and open the project file (the MVP) from its new location - MEP will complain that it cannot find the files like so
All you need to do is click the Folder button and point it to the new location of the files, you may have to repeat this several times if the files are not all in one folder.
MEP will then load the files once it knows where they are.
Save the project and then you can go back to it as often as you like now that is has been updated with the new location of the files.