When I try to copy and paste something from firefox to say notepad or word, it doesn't work on the first try. That is I go to firefox, select text, right click, select copy, then switch to notepad, right click, select paste, but it pastes not the thing which I copied just now, but whatever was in the clipboard before I copied. If after this I go back to firefox and copy that text again, and then go back to notepad, then it will paste correctly. So in order to copy paste something it takes me 2 tries.

This doesn't always happen this way, but only sometimes. So sometimes I can paste on first try, but sometimes it takes me two tries.

I am using firefox 7.0.1 and windows 7. Also it is not only with firefox, sometimes the same thing happens when I copy paste from other programs.

What could be the reason, and how can I fix this?

  • 1
    I have the same problem as well. If the community can't answer this well, I'll put a bounty on it.
    – bwDraco
    Oct 30, 2011 at 21:42
  • 1
    Realted: superuser.com/questions/145268/… Oct 31, 2011 at 4:44
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    @techie007 I ran that app, but it didn't do anything other than saying that everything is OK.
    – Sunny88
    Oct 31, 2011 at 8:20
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    Microsoft Office installed?
    – HaydnWVN
    Oct 31, 2011 at 10:40
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    @HaydnWVN Yes, installed.
    – Sunny88
    Oct 31, 2011 at 16:44

5 Answers 5


This is a known issue for Firefox. Check http://kb.mozillazine.org/Clipboard_not_working.

Section Removing AppInit_DLLS describes a solution to most common reason for delay. Renaming this registry key most probably will resolve the issue (it did for me on Firefox 7.0.1, Windows XP SP3). Check the contents of the same registry key after reboot. If the problem persists, the application that reappeared in the key is the one causing the problem.

Also, make sure the webpage you are accessing is not using keylogging script (which may be a desired behaviour) that blocks the usage of Ctrl+C, Ctrl+V.


This is a very random problem that exists in Windows since always. I normally hit Ctrl-C a couple of times when I want to be sure that the copy is really done. Otherwise, once out of about a dozen copy operation misses out.

However, in your case the frequency of missed-out copies seems to be much higher, this could be caused by some installed product that keeps accessing the clipboard. To copy into the clipboard, Firefox (or any other product) must obtain exclusive access to it, which is impossible if already accessed by some other program.

My first try would be to reboot in Safe mode and see if the problem is resolved. If it is, then some installed product is interfering, and you would need to find out which by trying. Such a product is probably launched during the boot, and a good tool to find and disable/re-enable startup items is Autoruns for Windows, which also can save and restore your current settings.

Any product that touches upon the clipboard is a suspect, especially clipboard extenders and similar.

If this problem only occurs in Firefox, it might be caused by an extension. Invoke "Mozilla Firefox (Safe Mode)" to check this possibility. If that's the case, disable extensions until you find the guilty one.

I suggest to take some precautions, such as creating a system restore point, before monkeying with startup items.


Have you made sure that your "clipboard" is empty? You may need to clear your clipboard via Microsoft Office - in other words, via Microsoft Word under the Clipboard task pane.

If this issue continues, you may even need to create a new shortcut on your desktop that performs this command:

cmd /c "echo off | clip"

You should enter in the shortcut location box when prompted to create the actual shortcut.

However, take this one step at a time - it's probably something simple. Are you up-to-date on your Windows 7 system? Try restarting - it's Windows!

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    Isn't clipboard supposed to clear automatically when I copy new thing? If every time before copying I will have to clear clipboard through clicking on that shortcut, it will be even worse than the current situation. Yes I am up to date on windows, and copy-pasting have been like this for months already.
    – Sunny88
    Oct 31, 2011 at 16:43
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    Microsoft Office (and i think IE8+) you can have multiple things 'copied'.
    – HaydnWVN
    Oct 31, 2011 at 16:51

Have cleared the clipboard, caches, and everything else and the control C command simply does not work the first time every time at random. Have even carefully tested this and found it may not work the second time either occasionally.

I suspect: as this is a system command and Windows has never been a real time OS since version 3.x the call to the system is not being captured when sent. This never happened in DOS or 3.x and has been around ever since real time was replace by looping, scanning (whatever). Consider how log it requires to send a CNRL C command and then consider the loop time of the interrupt driven loop. Other software operations can always get in the way blocking the command. Vanished into the digital mist because the hold time for the command is less than the loop time.

This is similar to the keyboard's left shift button requiring being depresses for some long time before a capital can be typed with another left finger. The command is not captured in the loop soon enough. In the keyboard I suspect this is an issue with the keyboard scanner routine in the keyboard's built in microprocessor scanner system though it could be Windows. Would require testing.

In short, even though you saved and used control C you better be darn sure that control V was used to paste it somewhere before you move on. Your save next save or typo could crash the editor you are using and the copied material may not even be on the clipboard unless you have pasted into some other software and know for certain it exist on the clipboard.

This is likely a basic function for a power user that will never ever work correctly as is the left shift key situation. Best to paste and carry on like pretty much everything else. Measure twice, cut one.

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    I've never had an issue with <shift> or <control> on windows (apart from a very rare "stuck" state). In any case, your answer is not an answer. At best it is a comment.
    – DavidPostill
    May 12, 2016 at 16:11

Firefox issues notwithstanding, just Alt-tabbing into an Office 2010 program was enough to empty my clipboard. The fix was unchecking the "Send to Bluetooth" COM add-on. In Outlook...

File --> Options --> Add-Ons --> COM Add-Ons --> Go. 

I'm using Office 2010, Windows 10 on a Dell Latitude E6540, but this would appear to be a very widespread and long-running issue. What a cracker. Fair play to whoever found this first.

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