Ie8.ie9 and ie10 in win7

At the beginning of this year, Microsoft opened Internet Explorer 10 for Windows 7.
Download the version. So far, three IE browser versions can be run on Windows 7.

Although windows and IE have gone through many versions of development, their traditional habits have not changed for many years:

1. Windows can only have one IE version at a time. After the new version of IE is installed, the old version of IE will be replaced. Different versions of IE cannot coexist in Windows (except for the green version );

2. for Windows, you can only upgrade or reinstall the IE version later than the existing version, but cannot run the IE installation program earlier than the existing version;

3. Windows all have a built-in default version of IE, such as IE8 for Windows 7. If all other versions of IE are uninstalled, Windows restores the default built-in IE version. The IE of the default version cannot be detached separately (you can only enable or disable
Windows function is disabled on the surface.

After clarifying these traditional habits, let's take a look at Windows 7. In Windows 7, the default version of IE is IE8,
Can be upgraded
Ie9 or ie10. Ie10
The installer only requires Windows 7 to have SP1, but ie9 is not required.

Therefore, you can upgrade IE8 to ie10 in Windows 7 without ie9, or
Upgrade to ie10 in Step 7.

Therefore, after ie10 is installed in Windows 7, if you need to uninstall ie10, you may encounter the following situations:

If ie9 has not been installed before, ie10 will be directly upgraded from IE8:

After ie10 is installed in Windows 7, the "enable or disable windows"-"installed updates" list in the control panel displays the uninstall options of ie10, you can perform this uninstall to automatically roll back to IE8 before ie10 is installed. However, this ie10 uninstall option cannot be rolled back to ie9, because we have not installed ie9 before. Ie9 cannot be directly installed even if ie10 is already installed. Therefore, if we want to roll back to ie9, we can only uninstall ie10 to restore
IE8, and then install ie9.

If ie9 has been installed before, ie10 will be upgraded from ie9:

If you have installed ie9 for Windows 7 before, you should have an uninstall option for ie9 in the "installed updates" list. After ie10 is installed on this basis, the "installed updates" list will not show the ie9 uninstall option, but only the ie10 uninstall option. However, although the uninstall option of ie9 is no longer visible, it still exists. If we choose to uninstall
Ie10 and Windows 7 will be rolled back to ie9 instead of IE8. After ie10 is uninstalled, the uninstall option of ie9 will also appear in the "installed Update" list again. In other words, Windows 7 always displays only one optional ie uninstall option. If we first install ie9 and then install ie10, and then want to roll back to the default version of IE8, you must uninstall it twice.

Finally, I will use a table to summarize the relations between all windows and IE version upgrades so far: