Please help me fix my computer!

Hi, this is my first post here. My computer specs are located at the bottom of my post. I cannot connect to the Internet via either wired Ethernet or wireless. I am unable to run Network Diagnostic Tool in Internet Explorer 9.0 and the Diagnostic Service Host is not running and unable to start as a local service. Also, the error message. “Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item.”: is displayed when I attempt to open any .exe file.

I tried to apply a registry patch to fix it and it worked at first and was able to open .exe files as normal, but when I restarted my system it began to display the error message again and now the registry fix no longer works in any way. I am aware that incorrectly editing the registry can be fatal, but this was only a patch to fix the .exe file associations.

I also receive the error message: “Failure to display security and shut down options: The logon process was unable to display security and logon options when CTRL+ALT+DELETE was pressed. If the operating system does not respond, press ESC or restart the computer by using the power switch,” when I press those keys. Occasionally a blank “green screen” is displayed when attempting normal start-up. The desktop as well as all icons are not visible and CTRL+SHIFT+ESC will not open Task Manager.

I can only access .exe files via Safe Mode, but cannot access Safe Mode with Networking or Safe Mode with Command Prompt, but. I can access the Command Prompt via Run > CMD from basic Safe Mode. I do not have any available System Restore points and do not want to perform a system reformat. I want to find a work-around. I have Malwarebytes’ Anti-Malware Pro, virus definition update as of Dec 3, 2011.

I cannot connect to the Internet at all to update the virus definitions. I cannot boot into normal mode to install any new virus software and copy over up-to-date virus definitions from another working computer because Windows Installer is not accessible via Safe Mode. No viruses, malware, and etc. was found when I ran a full scan via Malwarebytes with the virus definitions I have.

I am not sure what is causing all of these errors. I want to know if there are certain system files that I could copy over from another system of the same operating system and replace them in order to fix some of the errors if that is what might be causing them. I am on an Administrator account and have tried the “Run as administrator” option to open .exe files, but to no avail. There are no strange programs visible in Task Manager. All of my devices are functioning properly per Device Manager and all of the drivers including the ones for the network adapters are properly installed.

Any help would be greatly appreciated. I apologize if my post is too lengthy. I don’t expect everyone to read all of it and I have outlined the key errors I experience below my system specs.

Technical details of my system:

Computer make and model: Hewlett-Packard (HP) Pavilion dv4 Notebook PC
Operating system: Windows 7 Home Premium Service Pack 1
Processor: AMD Turion(tm) II Dual-Core Mobile M520 2.29 GHz
Memory (RAM): 4.00 GB (3.75 GB usable)
System type: 64-bit Operating System

Thank you for your help.

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Outline of erroneous behavior:

Error # 1: Unable to run Network Diagnostic Tool in Internet Explorer 9.0. Diagnostic Service Host not running and is unable to start. Cannot connect to the Internet via either wired Ethernet or wireless.

Error # 2: “Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item.”: is displayed when I attempt to open any .exe file.

Error # 3: Failure to display security and shut down options: The logon process was unable to display security and logon options when CTRL+ALT+DELETE was pressed. If the operating system does not respond, press ESC or restart the computer by using the power switch.

Error # 4: Occasionally a blank “green screen” is displayed when attempting normal start-up. The desktop as well as all icons are not visible and CTRL+SHIFT+ESC will not open Task Manager even though all of the system files are loaded.

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alphanumeric said:

If you go to Programs and Features in Control Panel, SP1 should be listed under the "View installed updates" option, upper left of the screen. You can attempt to un-install it from there. You could also try installing it again. You can get the full stand alone installer from here: Download: Windows 7 and Windows Server 2008 R2 Service Pack 1 (KB976932) - Microsoft Download Center - Download Details
Last two entries are the one(s) you want, one is for 32 bit and the other 64 bit.

I cannot use the SP1 installer because it says, "Windows 7 Service Pack 1 is already installed" and I am guessing that it can't re-install and overwrite the data. I navigated to Control Panel > Programs and Features > View installed updates and then to "Service Park for Microsoft Windows (KB976932) and when I click on it the uninstall link is missing, but only for that one particular update. I opened an elevated command prompt and entered "wusa.exe /uninstall /kb:976932" and received the error message "Service Pack for Microsoft Windows (KB976932) is required by your computer and cannot be uninstalled." I also noticed that when I check my Windows Update log that this update was marked as "failed," but still my operating system displays as having SP1. I am thinking that this is what corrupted my system. Is there a manual way to delete and remove the service pack files and registry entries? Also, my system didn't come with SP1 already installed.