Microsoft Security Essentials Installation wizard error code 80070643

Thanks all ! This is the reply I received which was very helpful.

Dear Afzal,

My name is Pavithra from Microsoft Security Essentials Technical Support team and I'll be assisting you with your case today.

For your reference, the case number that we will use while working on this issue is SRX 1116674459.You can reach me by e-mail directly at *** Email address is removed for privacy ***, using the Case Number above as the subject of your e-mail.

I understand that you are unable install the Microsoft Security Essentials and you receive an error code: 80070643. You have uninstalled all Antivirus programs and restarted your laptop several times. You received a message which says that you cannot complete Microsoft Security Essentials installation wizard.

If I have misunderstood your concern please do not hesitate to let me know. 

Afzal, I would like to apologize for any inconvenience that this issue has caused. I assure you that we will work together until the issue is resolved to your satisfaction.

This issue may be caused due to partially uninstalled third-party protection software on your computer or incorrect permissions to the System Files.

Please follow the below troubleshooting steps given below to resolve this issue:

Step1:

Please refer the below link to download and use  Live OneCare install cleanup tool if recently uninstalled Live OneCare from your computer(if applicable):

http://download.microsoft.com/download/4/c/b/4cb845e7-1076-437b-852a-7842a8ab13c8/OneCareCleanUp.exe

                                    (Or)

You can also refer the below link for Third-Party Anti-Virus Software Removal tools if you recently Uninstalled/Installed the respective Third-Party Anti-Virus Software from the computer(if applicable):

http://social.answers.microsoft.com/Forums/en-US/msestart/thread/407bf6da-c05d-4546-8788-0aa4c25a1f91

Please Note: The third-party products discussed here are manufactured by companies that are independent of Microsoft. We make no warranty, implied or otherwise, regarding these products' performance or reliability.

Step2:

Give Full Permission to All Users/Desktop:

1. Go to Start Search, type in CMD.

  Right click on CMD and Open as Administrator

2. Type each command below, pressing enter after each command. When asked to confirm press Y and hit enter:

   cacls "C:\Users\Public\Public Desktop" /t /g everyone:f

   cacls "C:\ProgramData\Microsoft\Windows\Start Menu\Programs" /t /g everyone:f

3. Exit the CMD.

Step3:

Obtain the latest version of the Windows Update Agent from the following link:

http://support.microsoft.com/kb/949104

Step4:

Re-Install the Microsoft Security Essentials on your computer:

Please follow the steps given below to Install Windows Clean up utility to remove the corrupted installation of Microsoft Security Essentials installed in your computer:

1.Download Windows Clean up utility from Microsoft Download Center:
   From http://support.microsoft.com/kb/290301/ 
2.Locate and run msicuu2.exe to install the Windows Installer CleanUp Utility.
3.Locate and launch the Windows Installer CleanUp Utility on the Start menu.
4.From the Windows Installer CleanUp Utility window, locate Microsoft Security Essentials and click the Remove button.
5.Once the all protection application has been removed, click the Exit button to close the utility.
6.Restart the computer

After trying the above troubleshooting steps, please follow the below instructions to download the appropriate version of the Microsoft Security Essentials for your operating system:

1. Go to the  below download link : http://www.microsoft.com/security_essentials/?mkt=en-us

2. Click on "Locales and Languages" Right below the Download button and you will find following three download options for different versions of  operating

  systems

  Windows XP 32-bit

  Windows Vista/WIN7 32-bit

  Windows Vista/WIN7 64-bit

  Note: Microsoft Security Essentials for Windows XP 64bit is not currently available for download

3. Select the appropriate version of the Microsoft Security Essentials and follow the On-Screen instructions to install the Microsoft Security Essentials.

4. Restart the computer after the installation completes.

Step5:

If the issue persists, follow the below steps to collect the Microsoft Security Essentials Installation Log for further research on the issue:

1.Please navigate to the following location and open the msseInstall.txt:

  C:\ProgramData\Microsoft\Microsoft Security Essentials\Support\msseInstall.txt

2.Click Select All on Edit tab at the top

3.Do a right Click on the Selected items and Click Copy

4.Paste it on the Explorer or Notepad and send it to us.

Note: If you find the C:\ProgramData to be hidden, follow below steps to enable hidden files:     

1.Close all programs so that you are at your desktop.

2.Double-click on the My Computer icon.

3.Select the Tools menu and click Folder Options.

4.After the new window appears select the View tab.

5.Put a checkmark in the checkbox labelled Display the contents of system folders.

6.Under the Hidden files and folders section select the radio button labelled Show

  hidden files and folders.

7.Remove the checkmark from the checkbox labelled Hide file extensions for known

  file types.

8.Remove the checkmark from the checkbox labelled Hide protected operating system

  files.

9.Press the Apply button and then the OK button and shutdown My Computer.

10.Now your computer is configured to show all hidden files.

Please try the above suggestions and let me know the results at your earliest convenience. If any of the steps are unclear or if you have any questions regarding the steps, please feel free to let me know. I will follow up with you as soon as possible.

We would also appreciate if you could please send us your phone number along with your convenient timing and the time zone in which you are located, so that we can contact you to know about the progress that has been made.

I look forward to your reply.

Thank you once again for choosing Microsoft Security Essentials Technical Support.

Best Regards,
Pavithra
*** Email address is removed for privacy ***
Support Engineer
Microsoft Security Essentials Technical Support

Important: "Having more than one Antivirus installed at the same time can cause stability and performance problems, please uninstall all Third-Party Antivirus applications at your own discretion before installing Microsoft Security Essentials."

If you need further assistance regarding this case, please write to*** Email address is removed for privacy ***, and we will follow up with you as soon as possible. Please remember to include the case ID number in the email subject heading written as: "SRX 1116674459".