Windows Was Unable to Complete the Format

Why Windows Was Unable to Complete the Format?

Have you ever encounter the message saying Windows was unable to complete the format when trying to format a removable disk like the picture shows below? In many cases, when we open an external hard drive, windows says that we need to format the hard drive before we can use it. However, if we follow the message to format external hard drive, Windows says it cannot complete the format. Why?
Possible reasons for Windows was unable to format removable disk are listed here:
1.The Drive Is Write Protected
If a hard drive is write protected, we cannot do anything except read it. Thus Windows was unable to complete the format.
2.The Drive Has Bad Sectors
Sectors are the smallest units for data storage. Thus, if a sector is damaged, we cannot read or write data stored on that part, so does Windows formatting and data recovery software. Bad sectors mainly comes from bad quality, excessive defragmentation, false operation, etc.
3.The Drive Is Physically Damaged
Physical damage often leads to storage device inaccessible, so Windows requires the external hard drive to be formatted and then saying it cannot complete the format. In this case, professional repair center should be the first choice if we have to save that drive.
4.The drive Suffers from Virus Infection
as external hard drives are removable drives and portable drives, thus they are easy to catch virus than internal drives. The virus often fills removable drives with dangerous files and makes them out of service.
5. The Drive Is Empty
In a certain case, a removable disk may become unallocated space, with only a drive letter for that drive so that it is visible under Windows Explorer. We know, formatting is based on partition instead of unallocated space, thus Windows is unable to complete the formatting.

What Should We Do Then?

It is recommended to recover data in the removable disk that needs formatting to a safe location before we carry out any further operation. The post How to Fix: You Need to Format the Disk before You Can Use It will tell you how to do that.
When Windows was unable to format removable disk, the first thing we need to do is to check whether there is partition on the drive. Go to Window Disk Management or use MiniTool Partition Wizard and you can see the disk layout intuitively. If there is no partition on it, create a new partition. However, if there are already a partition on it, we can see the partition is marked with RAW or Unformatted. At this time we will need to reformat that partition to make it available to use.
How to format partition?
We can go to Window Disk Management and then choose “Format” after right clicking on it. Then follow the instructions to format partition.
We can also use MiniTool Partition Wizard to do this job. Launch this application, choose the partition to be formatted and then select the feature named “Format Partition“. Choose the file system and cluster size, and the apply the changes.
Tip: For more information about how to deal with Windows was unable to format external hard drive, read How Do I Fix Windows Was Unable to Complete the Format.


Now we come to the end of this article which fours on why Windows was unable to complete the format and how to solve this issue. Now it’s your turn to check out whether this post is useful by doing it by yourself. For more disk/partition issues, just visit, you will find more than you have imagined.


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