M, I see nothing there that will help. USB is not the problem. For me it is kind of hard to plug everything into the back of the computer. I have 7 items that are USB. I plugged my Monitor into a Belkin Powered Hub. It and it still does it periodically. It did so with the monitor plugged into the back of the computer. The real problem is for somebody that cares, to look at the BIOS and fix it. But that is too much to ask. In a few weeks the E520/521 will be to old to bother with BIOS updates.

I have found that if you get a clicking noise it is coming from the HD. I believe bad sectors will cause this. I have done a low level format to get rid of the bad sectors and soon they come back. Once a HD starts to go bad there is not much you can do except replace it. Now when it happens I try to get it to boot up and transfer everything to another HD except the operating system and then replace the HD. Over the years I have had the Fatal clicking about 6 times. Don't just take my word for it, have someone, even yourself check the HD out.

Look at the HD light when you open the DVDRW. That is because your HD is being accessed. You will see it come on. I still think your problem is the HD. I would send it back too.

TD, Let us know how you make out. I think you are doing the right thing. Good luck