Perhaps my reply here is a little redundant but a little more info.

To answer the original questions,

No, the computer doesn't do it all the time. Although in the time since this thread started you may have found that out. My understanding is that what Windows does is identifies a new item and creates a registry for it. I have an impression that these drives, as well as the cards that are used in digital cameras etc., have some sort of internal serial number. When the computer recognizes a new one it reads for the type and size and other info and stores that on your computer. I have numerous memory cards, which I understand to essentially be the same as the thumb drive, jump drive or flash drives that are being discussed. A few of my cards are identical. Same size, manufacturer, made at the same time.... Every time I inserted a new one, the computer went through that routine. Now they don't cause that. Not even if they have been erased or reformatted. Further, whenever I buy a new one, or use one given me by someone else, the computer has to add that to the registry.

Second question, No, I don't think anyone can definitively say how long one of these will last. It could be virtually forever however I recall that a manufacturer can't guarantee something "Forever", assuming they aren't subjected to heat, moisture, crushing pressures, freezing etc. If they aren't abused and are handled carefully they should last a long long long time. Manufacturers will put a life expectancy on them to protect from liability if one should fail. There may be some expectation that inserting them and pulling them out repeatedly could, over time, wear out or damage contacts or pins... so they may come up with some expectations on that. Also, electronic chips, which is essentially what these are, are considered parishable. They could get brittle, circuts could delaminate and they could, concievably, wear out. They are solid state though, no moving parts so they should have a very long lifespan. Especially, as I said earlier, if you are careful, there may not really be such a risk. Still, what did Don's article say, 10,000 or 100,000??? reads and re-rewrites??? That is a lot of use.

I have some Compact Flash cards that I got with my first camera in 2000. AT that time, this was a big debate as some people were having troubles with their drives or memory cards after just months of some heavy use. Some had problems in just weeks. My oldest cards would now be over 6 years old and I have put thousands of pictures on them, writing and reading them repeatedly. They all are working just fine. I think a lot of problems that people might have is more the result of damaged data rather than the cards or drives. Remember to erase and reformat from time to time and never remove the drive or card from the device while it is reading, or writing or saving data. That will corrupt the data making the whole card, in some cases, unreadable. You might be able to recover some of your data but you will certainly loose some. Some of these devices have little lights on them. If that is illuminated, don't touch it till the device is no longer running.

I think that is one of the reasons for the selection on the bottom tray of your screen to stop or safely remove the device. That is how you tell the drive to stop operating so that you can safely remove it without corrupting your data. I don't know that you have to do that but it is a sure way to know that you aren't going to pull it out when it is reading or writing something. Wait for the confirmation that it is safe to remove.

As for the issue of leaving it on the computer, I don't see why not. Taking it off the computer??? It should be hot swapable meaning that you can switch them without turning off the computer etc. However note above about stopping them. While you may not need to do that, main thing is look at the drive and wait and make sure that it is finished writing or reading data before you take it off the system.

I have one myself, don't know the size off hand. Want to say 128meg. I got it with the idea of taking photos from the computer and transferring to another computer etc. However, I noticed one time that most of the kiosks in stores, ie, Walgreens, Target etc, don't have USB ports on the front. They have all the slots for Memory cards but not for the USB. That seems stupid. I do recall, maybe it was the computer at Ritz Camera, near me, does have the USB so that you can edit a batch of photos, dump them onto a Jump Drive or Thumb drive, whatever yours is called, and take it to some printers and print out the pictures. Very handy.