If I do a search on a file (or document) I know is there, and click on the Files (or Documents) symbol that appears, I get a dialog box with the message 'These files cannot be opened. Your security settings prevented one or more files from being opened'. If I click on the link in the dialog box, Why can't these files be opened?, the information I get does not seem relevant to a file in, say, the Pictures Library. What security settings might be causing the problem?

Can you elaborate more on your system, whether or not you did an upgrade to Windows 7 from Vista or if you did a clean install and then copied files from a backup source etc. There's usually an underlying factor involved. I suggest you restart, press F8 and then choose Repair Your Computer. Then restore the system to a fine previous status. MCSE, MCSA, MCDST [If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.]

Thank you cdobbs,I did a clean install back in October and I'm sure that Search worked OK then. It's only in the last few weeks that I have noticed the problem.I just tried an F8 and 'Repair your Computer' but did not do a System Restore as I don't know when the problem started.

You should be able to immediately test the results of your restore by trying the search again. Also if you had multiple backups, even if it only shows one initially, it will prompt you for which backup to restore (if you have multiple backups to the same location). Let us know. Keep in mind, when something doesn't work as before, something happened and you don't want to wait too long to do a repair/restore. Several weeks is a long time ;) MCSE, MCSA, MCDST [If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.]

Dear cdobbs,The earliest Restore Point is 31 December. I use a Tuneup program which I think deletes old restore point data. Going back to the original question, what security settings might be causing the problem?

This issue can be caused by software confliction. Let’s disable all startup items and third party services when booting. This method will help us determine if this issue is caused by a loading program or service. Please perform the following steps: 1. Click the Start Button type "msconfig" (without quotation marks) in the Start Search box, and then press Enter. Note: If prompted, please click Continue on the User Account Control (UAC) window. 2. Click the "Services" tab, check the "Hide All Microsoft Services" box and click "Disable All" (if it is not gray). 3. Click the "Startup" tab, click "Disable All" and click "OK". Then, restart the computer. When the "System Configuration Utility" window appears, please check the "Don't show this message or launch the System Configuration Utility when Windows starts" box and click OK. Please test this issue in the Clean Boot environment, if the issue disappears in the Clean Boot environment, we can use a 50/50 approach to quickly narrow down which entry is causing the issue.Arthur Xie - MSFT

Thank you Arthur Xie,I did exactly as you said. The problem is unchanged.One more piece of information;If I enter data in the search box, it's only if I click on the Programs, Control Panel, Documents or Files icon that I get the problem. If I click on 'See more results' at the bottom of the list, I do get a Search Results window with the appropriate file names displayed.I will now restore my Startup options to their previous values.