Seagate or Western digital External HDD?

With the WD Passport drive did you reformat the factory Fat 32 off of it prior to use or simply leave it as is when going to use it? As far as adding any new usb drive on 7 simply run to the Disk Management tool there and right click to assign it a drive letter to see Windows mount it as a new logical drive. That will stop the prompts for formatting it.

The same is seen for any other usb drive or device as well as seen when adding in a drive with data already on it to a second machine. The drive or device often has to be manually initialized in order for Windows to mount the volume and see it as a new logical drive.

Once you use a drive a few times however following a few full restarts Windows will typically remember the drive letter assigned. I found that was seen more with flash drives however as far as usb devices. One FDrive was given R for recovery when making up a data recovery stick with a 32gb flash drive.

After reboots, shutdowns, unplugged note the drive letter is still "R" for that same flash drive when plugged in again. Sometimes this will also work with external HDs as well. But don't count on that when electing to save Easy Transfers and/or system images there. External drives and devices connected by usb are still a bit volitile especially when not left plugged in constantly.

I recently bought one of these enclosures, very neat easy to slip in pocket, and usb lead in case, at present its only got a 160gb drive in it.

When buying the first of two external HDs here I was running into that when replugging it in when going back and forth between the two previous versions of Windows in dual boot at the time. Once reformatted to NTFS to be free of the software installer and to be immediately available on the two older OSs there and plugged in you still would see the occasional lack of initializing.

And talking about the prompt to format being seen lately that actually happened with an internal drive! Suddenly one drive seemed to vanish or simply be unavailable for some unknown reason. The drive would be seen but unavailable in the Disk Management tool as well?

Finally I went in and checked all data cables at both ends due to having just cleaned the case out. None were pulled out and in tight at the drive end and seemed be ok at the board end while still applying a little pressure to insure all were down in the ports there.

Surprize! The drive reappeared and has been normal ever since! The cable for that one didn't have to be lifted much as it must have been bumped during the cleaning. Now just imagine how one extra usb device plugged in one day tugs the bus down a bit or one of the usb ports is getting weak and... oops! Your external HD gets bumped out of Windows.

External drives can save your hide at times by stashing things safely away on them in case of an internal HD mishap. But counting on them being a dedicated Logical drive? You saw for yourself there.

Trying to build a server? BlueDove

I could use 6tb here but wouldn't have the need for that size enclosure. To transfer as well as backup things from multiple systems I simply went with a fan cooled usb enclosure for things like getting files off of the drives in older builds as well as large transfers.

The enclosure will accommidate ide as well as sata HDs regardless of the make and model drive you toss into it. Drives run cooler in the acomdata enclosure seen at Newegg.com - acomdata SMBXXXU2E-Red Aluminum 3.5" Radiant Red USB 2.0 Samba Enclosure Kit

Eventually I will get into the 2tb sized drives while presently have two GP 1tb drives as well as a pair of 1tb Sata III Black edition for the main storage internally. Vista is on one of the Sata II GP drives presently until that drive is eventually replaced with a another Sata II Black edition prior to testing the next version's beta when that time comes.

The model series of drives used in external enclosures are typically the energy conservative to start with whether usb or eSata. Since enclosures provided are typically not so well ventilated to start with you certainly wouldn't be running any Raptor drives in them!