I bought a 4 GB sony pendrive when i insert in cpu it cannot be located ,if i go in drives it shows insert?

1) first re-insert the PD to another USB port

2) Go to My Computer Right Click --> Properties ---> Hardware ---> Device Managers

If your USB is 1.2 complaints then some time the driver may not load

then the non-installed driver shows in Yello color. Right click on the Yell item and right click and choose properties Update Driver ---> Manually --> Select "STORAGE DEVICES" --- Next

Now you can open the Pen drive if there is no problem with the hardware

Use Auto Run Virus Remover

When you're talking about a 4GB flash drive, then it really doesn't matter, get whichever is cheapest, it's not like it's going to be huge investment or anything. It's not like you're talking about 64 GB USB 3.0 drive here. With that said, I've had good luck with Corsair and Kingston.

Open device manager, and change the drive letter.

Your computer may effected by Virus. Clean the system or format it once...

make sure you inserted the sticks all the way in... sometimes they feel in but they are really not.

or

you got the wrong brand for your motherboard...

your computer is infected by virus.