I have a late 2009 Mac Mini (Macmini3,1) with 2.53GHz processor and 4Gig of memory. I am running Snow Leopard. I purchased in January 2010. I have 4-6 external HDs connected to the machine while in normal running state. Two for Video, 2 for backup, and then plugin and remove others as necessary. Is there a limit to the number of external HDs I can connect, other then the number of USB ports? (I seriously doubt there could be any issue with having multiple external HDs, but...) I that were the case how would this have any impact on the internal HD? The reason I ask is when I tried to update the latest OS software it failed, and the last support person told me that it was not designed to have multiple external HDs connected. I have been working with tech support for the last few days, and currently my system just crashes every time I install the OS. (I tried a disk image, and now from install disk same thing) I believe it to be a HD failure, but how do I convince apple? When I call they just setup me up to reload the OS it says 20-50min, so they say call back if you have an issue. I am waiting on my 3rd call with them. Any advise for this call would be helpful. Side note: I have an external drive with OS X snow leopard installed and have booted that just fine and everything "just works" (including the latest update)! Sorry to ramble, but mildly annoyed with tech support at the moment!