USB stick doesn't mount, but is detected. How to repair?

I have a USB stick plugged in my PC, which is running Windows 7.

• In 'Computer', it won't show up.
• In 'Disk Management' (diskmgmt.msc) it won't show up (but sometimes it will).
• But in 'Devices Manager', under Universal Serial Bus Controllers, it is showing up.
• When trying to format, IOCTL error occured.

When plugging in the USB stick, the light on the stick starts to flash, plus the USB stick is listed on the Devices Manager screen, its properties can be viewed. The stick is detected as USB stick, but it is not seen as storage disk (not mounted).

I've tested it on multiple PCs and they're all saying the same.

How can I make the USB stick work again? Recovering the data on the stick is not in the scope of this question.

How can I make the USB stick work again?

You can't.

If no computer can "see" it, you can't use your computer to fix it.

If you had time, skills and resources, you might be able to disassemble it, identify the faults and repair or replace the faulty components. This would probably cost more than purchasing a hatfull of new USB sticks.

Update: the following advice seems to have been helpful for some people

Assuming that the drive has been properly partitioned and formatted, then this USB drive probably still needs to be enumerated for this computer. Open Control Panel. Go through Administrative Tools to Computer Management. Under Storage, click on Disk Management. Locate the USB drive and it probably needs to have a drive letter assigned to it. Do so (Right click and change drive letter - make sure it's not in use at time). Should take care of the problem.

Obviously this is only useful on those occasions when the device does show up in Disk Management (you said it sometimes did).

I had a SanDisk Cruzer Edge 8GB USB that was recognized but I couldn't use it. The steps that worked for me were to basically:

1. Go to: Control panel → System and Security → Administrative tools
2. Open Computer Management.
3. Go to Disk management on the left, and look at your drives.

Your problem will probably be that it is not allocated on your PC.

1. Right-click the drive
2. Click the text at the top
3. You will assign it and give it a letter (Choose one that isn't already taken, e.g. D)

It will assign it to your PC and you will be able to use it.

Summary in Bold.
I Also had this problem and just solved it by chance.
Yesterday I mounted my USB thru' a VMWare session on a SOE; today the same device would not mount [it is one of 2 devices I sync with daily as an offsite backup].
Looking at the Computer Management console (as described previously) I could see in 'Device Manager' the 'Universal Serial Bus Controllers' was actually recognizing the device, the icon displayed it with a small downward arrow!
... realizing that this entry came and went with the plug/unplug action, I knew this was it, and therefore nothing wrong with the ports.
After exhausting all the re-scan hardware changes, re-scan disk drives, disable, enable, re-install drivers, etc, etc., the last thing was to Uninstall this particular entry -> worked, then 'Scan for hardware changes', and what do you know, Windows installed 'new' drivers and it mounted immediately; Back to normal.

I had this recently. Reassigning the letter did nothing, until I ended the task Explorer.exe (Ctrl-Alt-Delete, choose explorer.exe, select End task) and start new task explorer.exe. The drive then reappeared.