Unable to install MSE error code: 0x80070645

[Qamar]

I have installed the windows XP pro with service pack 3 and I have also installed the Microsoft security essential in mine system. Yesterday while working on the MSE I have got the update and I have download and tried to install but while installing I have got the error code: 0x80070645 and mine system stopped installing. I have tried again to install but I got the same error. Now I don’t know how to solve this issue. Can anyone solve this issue and so that I can solve mine issue.

[Devasis]

I have same issue on mine system as well and you need to delete some registry key to solve this issue. To do this go to the start and after that make hit on the run and under the run type regedit and then hit the ok button. Now under the registry key go to the following location: HKEY_CLASSES_ROOT > Installer > UpgradeCodes > 1F69ACF0D1CF2B7418F292F0E05EC20B and here make right click on the 1F69ACF0D1CF2B7418F292F0E05EC20B and then delete it. After that now go to this location: HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > Windows > CurrentVersion > Installer > UpgradeCodes > 1F69ACF0D1CF2B7418F292F0E05EC20B and then again delete the 1F69ACF0D1CF2B7418F292F0E05EC20B registry key. Now go through your issue.

[Solomon]

While updating or installing the MSE make sure that you have removed the all other third party antivirus like real-time antimalware and free product install by the manufacturer while purchasing. If you didn’t removed then remove the all third party antivirus and after that use some cleanup tools and then restart your system. Now once you restart then try to install the update of MSE. I hope this will help you.

[Qamar]

Hello thanks for replying and I would appreciate your suggestion. I have gone through your all suggestion but it doesn’t help me to solve mine issue. I have deleted the both registry key and after that I went to update but it give the same error. And after that I have also removed mine real time protection and Norton and after that I have tried to install the update but it also gives the same issue. Now I don’t know how to solve this issue. Can anyone suggest on this and so that I can solve mine issue.

[MrChris-]

I would like to suggest you to uninstall the MSE and after that try to install the new again. To uninstall the MSE go to this steps: make hit on the start and after that click on the run. Now under the run type cmd and then hit the ok button. Now under the command prompt type the following and then hit enter after every command:

CD “C:\Program Files\Microsoft Security Essentials\Backup”
setup.exe /u

This will uninstall your MSE and after that restart your system and then install the MSE and after that install the new updates.

[GuillaumeGabard]

For Seven :

Remove registry key :

HKEY_CLASSES_ROOT > Installer > UpgradeCodes >26D13F39948E1D546B0106B5539504D9

For Windows XP :

HKEY_CLASSES_ROOT > Installer > UpgradeCodes > 1F69ACF0D1CF2B7418F292F0E05EC20B

And Install it !