Windows – Copy-paste stops working on Windows 7

Check out https://stackoverflow.com/questions/621577/clipboard-event-c

I don't think you can do more than there is available with the API, but this should be helpful enough to roll up your own Clipboard Monitor or request someone from that question to provide you theirs. Monitoring and showing the contents of the clipboard each time can be helpful whether to decide if something third-party is messing with your clipboard, from there you will have to identify the culprit by eliminating processes or something like that.

Does it happen constantly and consistently? That is, does it happen every time you boot and occur from startup to shutdown or does work sometimes?

If it works sometimes, then when it doesn’t, do you happen to have a browser open? If so, do you have some websites that you open regularly?

I ask because there exist programs (especially Flash applets) that copy an empty string to the clipboard in a loop in order to disable copying or pasting. I first discovered this on a web-survey site, but they also exist on other pages in an attempt to prevent users from copying content; however they also block copy/paste from working on the whole system until the applet is killed! (Yes, it’s not very effective copy-protection and incredibly intrusive and sucks CPU cycles, but… um, that’s it.)

What you can try is to view the clipboard to see what happens when you try to copy something. Windows 7 does not have the clipboard viewer (which was limited anyway), so get ClipSpy, then try copying various things to see if they end up in ClipSpy. Try copying some text, copying graphics (press PrintScreen to capture the screen), and try copying some files/folders. Do they show up in ClipSpy? Does the Paste option become available or does it remain grayed? By running these tests, we can narrow down what the problem is.