I installed Windows 7 a while back and it's been working fine. Recently I uninstalled a program, and after I rebooted all icons on the desktop are blank. When trying to launch windows explorer file browser (explorer.exe) I get an error message: "This file does not have a program associated with it for performing this action. Please install a program or, if one is already installed, create an association in the Default Programs control panel." When I try to open any app that's pinned to the taskbar, I get an error message: "Can't open this item. It might have been moved, renamed or deleted." I know these apps are still there. Also can't run regedit to check the registry. When I try to run Control Panel I get the same error, but the dialog title bar has a number that looks something like a GUID in it. I'm at a complete loss and don't even know where to start. It seems to be a problem with the registry, but I don't know how to even begin to tackle this issue. Any ideas?

Phillip - The first thing I would try - run system restore to a point prior to uninstalling that app... The 2nd thing I would do would be to run a repair install by doing an in-place upgrade - in other words - install windows 7 on top of itself. That would reset everything back to the defaults - without wiping out your data files or other installed apps. You may need to activate again, and you likely would need to do some configurations and download Windows updates - but it beats a complete fresh install.

I would try this:qo to http://www.winhelponline.com/articles/105/1/File-association-fixes-for-Windows-Vista.htmland download the fix for the "exe" file association.

Thanks for the suggestions, but nothing is working. I did the registry updates to fix file associations, but this didn't help. Also, since I can't run an .exe file, I can't do a re-install. It is possible to boot from the DVD, but you can only do a clean install from the DVD, it won't allow you to do an upgrade, which is what I want to do. I looked at the registry in my vista machine, and compared it to win7 and found that in the screwed-up win 7 installation, virtually all registry entries are missing from HKEY_CURRENT_USER. The only key under software is Microsoft, and it only has a couple of subkeys, one of which is for Explorer. TheHKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer key is missing almost all all its sub keys. There is not even a FileExts subkey. It's like something wiped out virtually the entireHKEY_CURRENT_USER section. I don't think it is a virus, because it happened after uninstalling an app. So I'm kind of stuck. I guess the question is: Is there a way to do an update install when booting from the DVD?

Phillip -Now that IS weird. What app was it that you uninstalled (If for no other reason than to help everyone avoid that same pitfall)? Normally, an uninstall shouldn't take out huge swaths of registry along with it. As far as doing anin place upgrade, the DVD should allow you to do that - as long as you're running the installation from boot, it should give you both options.

Hello Phillip,Before you do an upgrade-install open an administrative command prrompt and type sfc /scannow. Have your disk handy in case it finds any bad files as it will need it to re-write them.-Scott

Thanks for all the input. I've already bit the bullet and done a clean install. Relating to how the incident started: Technically I cancelled an installation that was in progress. The software was from NCH software. They have an on-demand installer, and I had inadvertently started the install for a product I didn't want. The problem started immediately after cancelling the install. For informational purposes, the bootable DVD will not allow you to do an upgrade if you boot from the DVD. The upgrade option requires you to have an instance of the Win7RC already running.

NCH software uninstall will Kill Windows 7. I experienced the same thing yesterday, and am currently reinstalling windows from scratch on my machine. I went against my instincts when I installed the software to begin with, because I do not like the "download on demand" type of installation that NCH utilizes. When I realised what I had installed wasn't what I expected, the uninstall killed my Windows 7 just as you described.

I have very similar problem, but it wasn't caused by NCH software. The only software I recently meddled with is NI Multisim, Eagle, KiCad and Protel. So if it's software problem, the cause is probably one of these. Not all exe files are missing, only some Microsoft ones (notepad, IE) and I can usually run them from command line - with the exception for all operations that need administrator privileges (including copying files to pendrive or showing most items in Control Panel). Plus WMP doesn't want to show my video files (says they're missing - it doesn't have any problems with playing music), while VLC runs them smoothly. Oh and Windows thinks there is no sound card in my computer (hence, no volume regulation), but it still plays sounds without a problem... Since I run out of ideas what to do, I'm probably gonna have to install new system on top of it. But since it's not only my problem, it would be nice if it was fixed... The system I'm using is Windows 7 Professional x64 from MSDN AA.

Thank you!Thank you!Thank you!Thank you!Thank you! to dean-dean.

The environment variable %windir% might be hosed. Check to see if it exists in a new command window by typing set w The command expression will list all envars that start with "w" My %windir% went missing after installing software. Maybe the installer hammered something. Using Win7 64 bit SP1. Noticed that a command window opened with Administrator privileges is showing %windir%. I also tweaked the system envars by adding a temporary variable.