During transfer computer can't detect cruzer anymore.

Ok, I have a problem that I can’t find anywhere.  I had a 8gb cruzer.  I would transfer a folder that had 1.5 gb of songs in it at once to it.  Half way through, it would freeze and my computer would tell me it can’t find the cruzer anymore.  So I shut computer off, removed the cruzer so I wasn’t just pulling it out while on.  Turned computer on, then reinserted.  Computer then acts like I disconnected it improperly and scans it and its good.  If I manually do items, its not a problem.  But a folder with 1.5 gb of songs is like way too much work to manually transfer.  It wouldn’t do this every time, so I eventually trashed it and ended up buying 3 16gb cruzers @ costco for 20 each on sale.  Two of them do the same thing, 1 has had no problems.  I have windows 7 home premium on a 5 month old HP.  I have tried different usb slots, and made sure the cruzers were inserted all the way.  When my computer tells me it can no longer find the cruzer, sometimes it still shows the drive is there and I properly disconnect it.  Other times it shows its gone, so I power off the computer.  When I reconnect the cruzer it always tells me I may have disconnected it improperly and scans it.  For some reason, 3 of the 4 just don’t always like transfers involving more than 1 gig.  Any input?

I have this same issue. I have a 32gb Sandisk USB Key and whenever I try copying large files it just goes to sleep. I have to unplug it and plug it back in to have it re-detected by windows.

I tried different formats for the drive. NTFS and exFAT both do the same thing.

I had thought about trying different formats, too.  B ut now I will not bother.  Thanks for that bit of info.

Try FAT32.

Correct me if I’m wrong, but they are fat32 right out of the box, aren’t they?  At least my computer says it is.

Some Windows machines go into a sleep/shutdown/power saving mode if there is no mouse or keyboard input after a period of time, regardless of what the hdd is doing.  Something to check.

Pen drive/USB is detected but not showing in computer