Hi, I am looking for a 500+GB External HDD. I already own a 100GB Maxtor model 3100 external HDD, which is currently unused. How practical is it to just replace the drive in my old Maxtor with a new bigger "internal" drive, keeping the original Maxtor enclosure, power supply, USB interface, etc? Just trying to save a few bucks here, since internal drives are generally cheaper than externals. Do I need to worry about using a different manufacturer's drive (maybe Seagate) with the Maxtor shell? How universally interchangable are replacement internal hard drives? Or is this approach more trouble than it's worth?

First of all is the enclosure AC powered? Does it accept 3.5" drives?
Your old external enclosure may not be 48bit LBA compliant. That means it may not be able to use a drive larger than 127GB. If it is compliant and was originally a stand alone enclosure then you can probably do what you want to. However, money wise I think you are better off just buying new and selling the old drive.

Why are you not currently using the 100GB external?

The brand of drive doesn't matter. The interface is what does matter. For instance if your current drive is ATA/IDE and supports 100mbps transfer you can use any drive like that. Some IDE/ATA drives are 133mbps transfer. The drive would only run at the 100mbps. This isn't an issue as the USB transfer speeds are less than either of the mentioned ATA speeds anyway.

If you with to futureproof your purchase you could consider buying a SATA enternal drive enclosure. The link below is for a SATA II enclosure that can be use as both a USB and an eSATA connection. Right now you would use the USB but in the future when you get a new computer you could be sure at that time the computer has eSATA ports. Then the drive would connect externall but run at the same SATA II speeds as if it were installed internally. The second link is for SATA II drives to pair up with the enclosure.

http://www.newegg.com/Product/Produ...

http://www.newegg.com/Product/Produ...

Thanks OtheHill for the prompt advice. It is indeed AC powered, and contains a 3.5" IDE drive. I have no clue as to whether it is 48 bit LBA compliant though. Seems like it would not need to be if it was sold with a 100GB capacity. It is at least 2-1/2 years old, and there weren't many consumer drives around at that time that were bigger than 127GB. (This was not sold as a separate enclosure, but a ready-to-use 100GB external hard drive.) I think I'll take your advice and buy a complete solution that I know will work right out of the box. And maybe hook this old one up and move my music & photos to it. I'm not using it now because I just recently inherited it. My core problem is I have outgrown the 250GB external drive that I use to back up everything else, and thought maybe this 'dinky' 100GB drive could be upgraded for less than the cost of a new larger one. Thanks again.

Well, one thing to keep in mind is this. You should maintain AT LEAST two copies of any data you don't wish to lose. IMHO burning to optical disk is one of the safest ways to protect data. Making duplicates to store in more than one place is fast, easy and cheap. Doing that allows you to use the external as the primary storage medium.

A external drive is no different than an internal one in one respect. It is just as likely to fail. There is an addage with harddrives. "It is not a question of IF your harddrive will fail but WHEN will it fail. In addition to what I mentioned above there are also external solutions that have 2 mirrored drives in one enclosure. These units can be used as two drives separately or a mirrored ARRAY. This redundancy costs more but is safer.

One other thing to note. Leaving an external drive powered and connected to your computer 24/7 exposes the external to the same risks as an internal drive. If your really want to protect the data you must isolate it from the computer when not writing or reading from it. If the drive is your second copy this isn't a problem. If the only copy you need to re-access how you store your data. If you are interested in a mirrored solution post back and I can provide some links.

Well that sounds quite complex, why not just buy a new external, their price are quite nice now, I have noticed that the Vox 500GB 3.5in USB 2.0 is $90:
http://www.dealstudio.com/searchdea...

I just gave the the pros and cons of your options.