When I try to install the latest version of CCleaner or Defragler it tells me that I need Windows XP or higher. I am running Windows 7. How do I fix this?
First make sure you either got the installer from here
http://www.piriform.com/ccleaner/builds
or here
http://www.filehippo.com/download_ccleaner/
Do you have service pack one for Windows 7 installed? Is it Win 7 basic, home or pro?
Make sure the installer isn't using compatability mode for some reason (right-click on installer and select properties, then compatibility tab)
If all else fails, you can run the portable CCleaner
Windows Help reports Windows 7 Home Premium, Service Pack 1. No compatibility mode. Please note that CCleaner versions below 4 installed and ran just fine, so I would assume that something changed in the installer. Is there a registry key I should look at?
Further info that may help. Portable version of CCleaner runs OK. However, portable version of Defraggler gives me the same error message.