A No Bootable Device Found error means your computer’s BIOS or UEFI — the firmware that starts your hardware — cannot locate an operating system to load.  Usually, you’ll see this error when you’ve changed your computer’s hardware in some...

Windows will issue a “checking file system” message when it encounters errors that prevents it from accessing your data; if you’re stuck on a screen that says Checking file system on C: (or another drive letter) for hours, the operating...

The “Semaphore timeout period has expired” error (System Error 121) occurs when your computer attempts to transfer data to or from an external drive or network location and fails to receive a response within a set timeframe. You’re most likely...

Error Code 0xc000000e is a Windows Boot Manager message indicating that the operating system cannot locate the files required to start the computer. Usually, the Boot Configuration Data (BCD) has become corrupted, is missing, or is pointing to a drive...

A device which does not exist was specified is a critical Windows error that occurs when the operating system loses its hardware connection to a storage device in the middle of a task.  When this message appears, the communication link...

“The parameter is incorrect” (Error 0x80070057) indicates that Windows can’t access a device, or that key system files are corrupt. Learn more.

You’ve decided to use RAID, but you’re not sure why RAID 5 is the most popular choice for home users and small businesses. Isn’t RAID 6 better? RAID 6 offers a higher level of fault tolerance than RAID 5 because...

While RAID 6 offers higher fault tolerance than RAID 5, its error correction system creates unique challenges when multiple drives fail or a controller malfunction occurs. Successful data recovery requires correct identification of the parity rotation and the exact point...

You need to recover files from a hard drive, solid-state drive (SSD), USB stick, RAID array, or some other type of storage device — but you’re not sure what to do next. Logically, you know that you’ll need to work...