The drive f: is not formatted. Do you want to format it now? (WIN XP)

Did it ever happen to you, that you lost your access to external usb storage medias, such as USB dongles, external hard drives, different memory cards and other devices, capable of storing data?

It happened to me this monday. Suddenly my computer didn't recognise any USB storages I had. Before that I scanned my computer with Avast antivirus and it found some infected files which it couldn't repair, so I deleted them. First I thought something is wrong with my USB dongle, but after some testing on other computer everything was working normally. I tried with another USB dongle with no success. The computer recognises the drive and assignes the drive letter (for example f:), but the content cannot be accessed and "Disk not formatted" error occurs. Of course I clicked "cancel" not to format it.

Since I didn't know any solution, i went searching the Internet to find a solution. Unfortunatly noone form dozens of forums gave me the solution that would work, which seemed quite strange to me. I tried System restore without any success also. What ever I tried, nothing worked. Since I didn't want to format the computer and install a fresh version of Windows XP, I was thinkig about what did Avast delete? I checked in windows/system32 folder and the file ntdll.dll was there, so I decided to replace it. Of course Windows doesn't let you replace the file, so I had to go by steps, which wil most probably help you too.

- Find the file ntdll.dll on a computer with healthy Windows XP and copy it to your USB dongle
  (c:/windows/system32/ntdll.dll) 
- Download Hiren's boot CD on this link
- Unzip and burn ISO to a CD
- Insert the CD v you drive and restart your computer
  (CD boot must be enabled before booting from hard drive)
- Choose "Mini Windows XP" from the menu
- When the system loads, insert USB key in your computer
- Copy (and replace) the file ntdll.dll to folder c:/windows/system32/
- Take the CD from your drive and restart the computer

That's it. The computer should work normally in all aspects now, including your USB drives.

I hope this post saved some minutes of your time. Feel free to leave a comment with your exoeriences.

Yours Lucky.