Is it the quality issue?

[ruthnin]

one of my friend bought a USB flash drive(Nonbrand) and he wants to test the drive before placing big orders. everything is ok after a few tests but problems occured after he pull out the drive a few times while transferring files. The thumb drive is dead and even can not format.

Is it a defective product or it can not be pulled out while copying data?

Thanks.

 

[Ubrales]

Welcome to Tom's Hardware Forums!

Thumb drives should not be pulled out while it is writing data.

Regarding defective thumb drives, there are plenty of fake drives being sold. Buy from reliable merchants.

 

[Traildriver]

It's a good "Rule of Thumb" to stop the Thumb drive by right-clicking the Thumb drive icon in the Notification area and following the prompts to stop the Thumb drive before removal. It's not required in Win 7 but it's just good practice to do so so you do not corrupt the data or fry the guts of the drive with an untimely removal. Following this "Rule of Thumb" allows the hardware to do it's job.