Now it is time to test whether there are bad sectors on the drive bringing Steam disk write error Windows 10/8/7. Select the disk that has Steam installed and reports Steam disk write error and then choose Surface Test from the Check Partition group. In the new emerging window, click Start Now on the top right corner to begin the check.
Note that if there are read errors found, they will be marked with red color.
The Steam client automatically detects its current region and uses content servers located in that region.
Sometimes, servers in a specific region may be slow or overloaded, leading to Steam disk write error while downloading.
Go to the file location of Steam (default location is C:/program files/Steam). Head to the Compatibility tab in properties and make sure "run this program as an administrator" is ticked. In short, he just solved this issue by going into Program Files (x86)/Steam/steamapps/common and simply deleting a file titled Fallout that was 0KB in size.