External hard drive not reading on my computer

My computer will no longer read my WD Elements external hard drive.  I am operation on windows vista.  The power light on my external hard drive flashes but when I connect it to my computer (and I have tried 3 different computers), the computer does not see it.  I thought my USB cable was bad and purchased a new one and it still is not working.  I am a photographer and all my 2010 work is on this hard drive.  Any suggestions?

Is the drive plugged directly into a wall outlet not using a power strip? If it is still not recognized and you drive is still under warranty it should be worth replacing. You can also contact WD tech support on a list of data recovery agents to be referred to for recovering the data. Or check out some other people on the forum who utilize data recovery software.