Too bad. I use two flash drive of SanDisk 4Gb ...
339966
I bought this flash drive on October 21, 2014 and by March 2015, it stopped working. At first, the drive become write protected. I tried formatted it by using Kingston format utility but the program could not format the drive because it was write protected. I still can read files from the drive so I keep using it for a while. After 1 month, the drive was completely dead. My PC is no longer recognize the drive when I plug it it. Too bad. I use two flash drive of SanDisk 4Gb and 16Gb and they are still working after 4 years.
3605831
With two different samsung 16gb microsdhc class 2 cards, both have become corrupted needing to be reformatted at least twice. They are also extremely flaky, and some devices will not accept them most of the time.

Both are absolutely ridiculously slow, with a 150kB/s write speed, far short of class 2 spec (min. 2MB/s).

edit: I should add that these cards were used mainly in two separate devices when they became corrupted, and the slow reading times were on two different desktops.
4864327
I had ordered 3 of these (trying to buy 6 and the system won't allow me). One of the drives was inaccessible and the laptop kept on asking me to format the drive. I bought 3 SANDISK Ultra and couldn't be happier. Lexar used to be my favorite brand especially for camera memory. I would like to give some credit, tried to trasnfer some files on the remaining2 drives and found the transfer speeds exceed the Sandisk ultra  by quiet a bit. But I prefer reliability over speed especially with so much data I don't want the usb stick die on me.
1259047
I never have had much trouble with SanDisk flash drives and will probably stick with them!  Thank you very much!
1895360
I appreciate the SanDisk brand when it comes to storage and I have never had reason to mistrust it in terms of quality; however, the low price of this unit comes with a few penalties.

I actually bought this to transfer my account and save game information from my old (second generation) Xbox 360 to the new "slim" 360.  It did that without a problem, and the 8 GB of storage was plenty for that purpose.  The embedded LED that shines through the white slider is bright and very easy to see. Essentially, it does exactly what a USB stick is supposed to do in that respect.

The locking mechanism for the slide is a bit weak or perhaps "fussy" is the better word.  There were a few times when I had to hold the slider in place in order to insert the drive into the USB port or else the plug would retract back into the case.

The most annoying thing about this drive is that it's ridiculously slow.  I've tried using it in several different systems that I own, and none of them got more than 3 MB/sec out of this drive.  A 2 GB Patriot USB drive of mine that's probably five years old transfers at roughly 16 MB/sec.  A 4 GB PNY that's about three years old transfers at around 24 MB/sec.  Yet this BRAND NEW SanDisk drive transfers at 3 MB/sec!  That's completely unacceptable!  (And I just verified all of these speeds as I was writing this review.)

At 3 MB/sec, it would take at least 90 minutes to transfer 8 GB worth of data to the USB drive then to the destination system.  I could actually transfer that same amount of data with my 4 GB PNY - copy 4 GB to the drive, copy that to the other system, copy the remaining 4 GB, and copy that to the other system - in less time than it takes just to copy 8 GB to the SanDisk drive.  That's absolutely appalling.

If you're looking for a decently priced USB drive and you don't care about speed, this will work just fine; however, if you're looking for a USB drive with any kind of respectable speed, stay far away from this.
4357413
this may be 10th or more sandisk flash drive since they sell on 256mb thumb drive, they make the best flash drive period
2309510
My second one just failed. (Mine is the 4GB HT203) Each one lasted about three months as a Vista Readyboost device. I probably unplugged the thing(s) a total of ten times. I always use "Safe Remove" for all of my temporary storage devices, of which I have many.

They go bad over time. Too little time. I have other flash drives and they all fail eventually, but this one is the worst. It isn't worth the shipping and headache to keep shipping them back for RMAs.

I tried the low-level restore/reset/format program several times on both sticks. Once they go, they are gone!

For regular file stuff, go with another stick.

For Readyboost, I would suggest that if you have a pagefile on a 7200RPM drive (pretty much the standard), you get next to no benefit from Readyboost and possibly even take a performance hit. My page file is on a RAID 0 between two 7200 RPM Seagates over SATA2 that are dedicated to paging and temporary files and where the pagefile is on the outer tracks of the platters. All OS, Application and storage is done on other drives. I don't even think USB2.0 at its highest throughput can tranfer data as fast.

I got off on a tangent. There is probably no computer that comes pre-loaded with Vista that doesn't have a 7200RPM disk drive and there is maybe one scenario in 100 that might give you 2% - 5% performance improvement from using Readyboost. Certainly not enough to warrant a dingdong sticking out of the back or side of your computer asking to be broken off.

That is not to say that memory installed into the memory bus can't help. With Vista, I would say 2GB should be the minimum. Memory accessed through the memory bus is much faster than USB or SATA, so no Flash Drive or Disk Drive can come close. It is more expensive than Flash Drive memory, but worth it and these days it is pretty easy to install even in a notebook computer.

I said too much already.

Bottom line is that I am very disappointed with the MTTF of this product.
4039082
I bought 5 of the PNY 128 gb 3.0 flash drives. ONLY 3 can be read by my computer the other two became corrupt and will not work on other computers either. When I was adding files to drives I wrote with marker on them so I couldn't return them. I WASTED $80 on the 2 that stopped working properly. Very upset and will never buy these again. I feel the 3 that work will end up being corrupt too. If that happens then I would of wasted over $200. I went online to and saw others had same problem. If I didn't write on them with marker I would DEMAND my money back.
2091179
What a load of bull. There's clearly some buffer that makes it appear to write fast (60MB/s) for the first ~10 seconds. Then it goes down to 10MB/s. Slower than USB2. Avoiding Sandisk from now on.
1066003
I would have liked to known how to make sure you get use of all 16GB of the flash drive. The first time I used it I only could use about 4.9Gb of the drive had to do some changes to get more space out of it to use it. My system is about 4 years old and needed changes to see more of the drive. Once got that resolved all is well. I use it to back up my system.
3114152
Bought these several months ago.  They seemed to do OK for a few weeks of light use.  Copying a few small files back & forth was no problem.  However, when I try copying a couple thousand small files or 13-14 GB of larger files onto the 16 GB version, the drives turn "read only" in the middle of the transfer.  I have run scans on them, re-formatted them as FAT32 and NTFS, tried different allocation sizes, etc.  Same thing with all 3 drives.  When I use my 8 year old, 16 GB Corsair Flash Voyager, the same data that chokes these drives, will copy fine to it as well as using a SanDisk 16 GB micro-SD card.
4114244
I have not had good luck with these products from SanDisk. I won't buy any more of them. After an update I lost everything on the drive so I will erase their software and just use it as another storage place.
3003389
After 3 months the file allocation table got corrupted.  Several files were lost new files could not be saved.  A reformat seems to have allowed it to be used again, but who knows how long it will last.  I have never had a problem like this with any other flash drive I have used.
4089111
I used it a couple of times and then for some reason it would tell me that the disk was only 100mb and I could not store anything on it any more.  I also could not format it.  My computer would not recognize as 8Gig so alas I had to trash it.  Generally I have had good luck with SanDisk so I'm not down on them, I'm guessing I just got a bad one.
2677356
Awesome except you get 460 gigs. Where do the other 40 gigs go? You lose more gigs than the older platter drives. Maybe Santa will visit the Island of Lost Gigs one day and find those gigs a home.
545018
Every time I delete something from this SD card or add something new it reverts after and hour or so and all my new data gets deleted.
I think it is broken because it has been doing this for about two weeks. I bought this about 4 weeks ago.
What happened I don't know, maybe a delay defect was set into place from the shipment date but this product does not work properly I should have stuck with SanDisk their product don't fail on you when you least expect it... I've lost a couple pictures and videos that held some memories that were very close to heart...
All I can do is shake my head because retrieving them is impossible.
4538592
People who are 5 star raving about this flashdrive have not yet needed it for its advertised capacity. I still have XP Pro 32 bit in everything so the Windows 7 problem does not affect me.

I just bought two of these as full backup devices for my two home PCs. Each PC needs approx 6gb of space to complete the backup. I figured at 8gb of capacity I was home free with room to spare; one drive for each PC. WRONG! At exactly 3.99gb, they quit taking data and were full. The results were the same whether used right out of the package, formatted quick or formatted slow. An encryption problem or not, it is deceptive marketing.

I will now consider these as 4gb drives and use one and a half of them to backup one PC.
Thanks,
MR
**********NOTE
Update: Found that this problem is caused by the flash drive being formatted in FAT. If you reformat to NTFS it will work fine and fill to capacity. However 3 of my 4 computers would not do it. Only my new ASUS laptop did the reformat flawlessly.