File

Check to see if the file is read-only.

To do this, open Explorer, locate the file, and right-click on the filename. Select properties. You will see the file attributes at the bottom of the properties dialog.

If the Read-only attribute is set, toggle the check-box off.

In rare cases, the entire folder (or drive) may be set to read-only. In these situations you may need to clear the read-only state from the drive or folder, following the steps above, but going into the properties of the folder or drive.

Before changing the read-only state on a folder or drive, consider if there were good reasons why read-only was set before clearing the flag. Also consider if another writable location would be better.

If the file resides on read-only media such as a CD, DVD or Blu-ray, you must select a different drive to save the file.

Some removable drives and media may also have a physical write-protection tab. For example, diskettes have a square hole that when covered, makes the diskette read-only. Some USB flash drives also have a switch to make them read-only.

A command line utility cacls.exe is used to view and set the owner of a file. You will need to be an administrator to make Access Control List (ACL) changes. The following steps can be used to view and set the file's ACL:

1. Open a command line box by selecting Start, Accessories, Command Prompt.
2. At the command prompt type cacls, followed by the path and filename of a file you can access (not the one you are having problems with).  This shows you the current owners and the user access rights. For example, on a default XP system, entering cacls c:\Windows\Notepad.exe, the results would appear similar to:
   
   

   C:\WINDOWS\NOTEPAD.EXE	BUILTIN\Users:R
   	BUILTIN\Power Users:C
   	BUILTIN\Administrators:F
   	NT AUTHORITY\SYSTEM:F

   
   
3. In this system there are three owner categories, called Users, Power Users and Administrators. The letter following the owner category is one of four types, R for Read-only, W for Write, C for Change (also write), and F for Full control.
4. Run cacls on the file with the problem. If the owner rights are too limited or there are no owners associated with the file, you can fix it using the /G (Grant) option. For Notepad, if we wanted the Users owner category to be able to read/write and overwrite the file, and leave the others as-is,  at a command prompt, we'd enter:
   
   cacls notepad.exe /G Users:F "Power Users":C Administrators:F

It will return:

Are you sure (Y/N)?


Enter Y for Yes.

In this example, we included all three owners, since if you fail to include an existing owner, it is removed!  If your owner name has a space in it, you'll need to enclose the owner name in quotes as we did for Power Users. The owner names, the user access right letter and the option /G are all case-insensitive.

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