Problem

Notepad fails to open text files from read-only media (such as VirtualBox shared folders configured as read-only) with the error message "The medium is write-protected." The file is not displayed in Notepad. However, WordPad opens the same files without any errors.

Root Cause

The issue is in the DoOpenFile function in base/applications/notepad/dialog.c. The function uses OPEN_ALWAYS when calling CreateFile:

hFile = CreateFile(szFileName, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
                   OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

OPEN_ALWAYS attempts to open a file, and if it doesn't exist, it will create it. This fails on read-only media because the system cannot create a new file, even though we're only requesting GENERIC_READ access.

Solution

Change OPEN_ALWAYS to OPEN_EXISTING in the CreateFile call. OPEN_EXISTING only opens existing files without attempting to create them, which is the correct behavior for opening files for reading.

hFile = CreateFile(szFileName, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
                   OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

This change makes Notepad's behavior consistent with other text editors like WordPad.

Testing

After this fix:

• Files from read-only media (VirtualBox shared folders, CD-ROMs, etc.) should open successfully
• Normal file opening behavior should remain unchanged
• Non-existent files will properly fail to open (which is the expected behavior)

Files Changed

• base/applications/notepad/dialog.c - Change OPEN_ALWAYS to OPEN_EXISTING in DoOpenFile function