All excel files opening in read only mode in Windows 7

Go to the folders involved, right click, properties, untick the read only.

Question? Were these excel files created in another version of Excel that what your using?
Or were they attachments to emails?

questions, Questions..

Rich

The only thing I can think of is that the 1's downloaded need to be 'Unblocked'. Right-click and select Properties and there should be an 'Unblock' button, just click it.

Also, when you're saving files they may have accidentally been set to save as read only. Try the following...

1, Open an Excel Spreadsheet
2, Click File > Save As
3, Click the Tools dropdown then General Options...

Check to see that the 'Read-Only Recommended' hasn't been selected by accident...

1. Which version of Outlook (Office) are you using?

2. Do you save the attachments to your hard drive before trying to edit?

I also had the same problem, try disable file preview from Explorer, see attachment...

It seems for some reason the file is "locked" or something similar when preview is enabled, in any case disabling this feature solved the problem for me, no more Excel file opened in read-only mode.

Lots of information here:
Outlook 2010 & Read-Only Attachments
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Solution - Edit Message Method

Video Tutorial

How to Edit Attachments in Outlook 2010

If you put the email message into Edit mode you can edit the attachment and save changes back to the original attachment on the email message. You need to remember to save the attachment when closing AND save changes to the email message as the copy in the securetemp folder will be deleted when you close Outlook.
If you add the Edit Message button to the QAT or Ribbon, its very easy to get into Edit mode. To add the command to the QAT (or ribbon):

1. Open a message
2. Go to File, Options, then choose either Customize Ribbon or Quick Access Toolbar
3. Select All Commands from the Choose command dropdown
4. Click in the list of commands then press E on your keyboard to jump down to the Edit commands.
5. Find Edit Message and double click on it or use the Add button to add it to the QAT or Ribbon.
6. Click OK to return to the message.

The next time you need to edit an attachment and save the changes back to the message, open the email message, click the Edit Message button then open the attachment.
Remember: you need to save and close the attachment then save and close the email message for the edits to be saved. If you don't want changes saved (such as when rotating images), close without saving.

Solution - Disable Attachment Preview

You can make many attachments readable if you disable Attachment Preview. With this disabled you will lose the ability to view attachments in the Reading pane or open messages - you will need to double click to open them in their application.
Go to File tab, Options, Trust Center:

1. Click the Trust Center Settings button
2. Select Attachment Handling
3. Add a check to the "Turn off attachment preview" option.

Note: this disables preview for all attachments. If you like the attachment preview feature, use the Edit message method.

Solution - Images viewed with Windows Photo Viewer

A workaround for those using Photo Viewer exists: in Photo viewer, click on File, Properties, General tab then clear the Read only check. Repeat for each image.