如果您计划将Apple设备升级到 iOS 11，您可以选择执行正常升级或执行全新安装。如果您要升级 6S 或 iPhone 7 等相对较新的设备，正常升级可能就可以了。
但是，在旧设备上，全新安装可以帮助设备运行得更快、更流畅。即使在我的 iPhone 6S Plus 上，当我执行全新安装时，一切都变得更加快捷。执行全新安装时，您可以遵循两条路径。
这两种方法都涉及擦除手机并将其恢复到最新版本的 iOS，在本例中为 11。一旦这样做，您可以将手机设置为新 iPhone，也可以从备份中恢复。如果您真的想从头开始，您可以再次手动下载所有应用程序并将所有内容设置为新的。这里最重要的是您将丢失所有旧消息和健康数据，因此如果您想要这些，那么选择非常明确。
如果您恢复备份，您将获得所有旧消息、健康数据、应用程序、下载的音乐、照片（如果不使用 iCloud照片(Photo)库等）。值得注意的是，只有从iCloud 备份或来自加密的 iTunes 备份。
全新安装 iOS 11
您要做的第一件事是在您的 PC 或Mac上打开 iTunes 。您无法直接从 iPhone 或 iPad 执行全新安装。从设备本身，您只能升级到最新版本的 iOS。
打开 iTunes 后，连接您的设备并单击顶部显示的手机或平板电脑图标。
此屏幕将为您提供有关手机的基本信息，例如型号、序列号、电话号码等。在右侧，您将看到已安装的当前 iOS 版本。
就我而言，它是 10.3.3 版本，它是 11 之前的最新版本。如果这是您第一次连接它，消息会说您的 iPhone 软件是最新的。继续并单击检查更新(Check for Update)按钮。
应该会弹出一条消息，说明有新的 iPhone 软件版本 (11) 可用。在这里，您要单击仅下载(Download Only)。不要单击下载和更新，( Download and Update)因为(not)这只会将您的手机更新到 iOS 11 而不对其进行格式化。
等待(Wait)下载完成，然后单击“恢复 iPhone”( Restore iPhone)按钮。另一个按钮应该已更改为只是Update而不是Check for Update。
如果您尚未备份手机，系统会在您恢复软件(restores the software)之前询问您是否要备份手机上的设置。如果您打算之后恢复手机，请务必选择备份(Back Up)。
备份后或如果您单击不备份( Don’t Back Up)，将出现另一条消息，要求您确认是否要恢复和更新。这意味着它将恢复到出厂设置并安装最新版本的 iOS。
当您单击 恢复和更新(Restore and Update)时，将出现一个 iPhone软件更新(Software Update)对话框，其中显示了 iOS 11 中的所有新功能。如果您愿意，请随意阅读或保存。(Feel)如果您在前面的步骤之一中单击了取消(Cancel)而不是仅下载，则( Download Only)单击下一步(Click Next)，iTunes将开始下载更新，或者它将开始恢复过程。
您还应该在手机上看到它显示正在恢复(Restore in Progress)。这将需要一些时间，因此请随时离开，稍后再回来。恢复完成后，iTunes 上的屏幕应更改为“欢迎使用您的新 iPhone(Welcome to Your New iPhone) ”页面。
在这一点上，您可以选择我上面提到的两条路径之一。如果您想要最快且体积最小的设备，您应该选择设置为新 iPhone(Set up as new iPhone)并仅下载您需要的应用程序并从头开始设置所有内容。如果您不想花费所有时间重新设置所有内容，只需选择从此备份中恢复( Restore from this backup)，然后选择您在恢复之前创建的备份。
就是这样。这两种方法都构成全新安装，因为您正在擦除手机并安装 iOS 11 的全新副本。即使您在全新安装后恢复备份，您的手机仍然会比您直接升级到 iOS 11 运行得更好你的设备。如果您有任何疑问或遇到任何问题，请随时在此处发表评论！享受！
How to Clean Install iOS 11 on iPhone or iPad
If you’re planning to upgrade your Apple devicе to iOS 11, you have the option to perform a normal upgrade or perform a clean install. If you’re upgrading a rеlatively new deνice like a 6S or iРhone 7, a normal upgrade will probably be just fine.
However, on older devices, a clean install can help the device run faster and more smoothly. Even on my iPhone 6S Plus, everything was a lot snappier when I performed a clean install. There are two paths you can follow when performing a clean install.
Both methods involve erasing the phone and restoring it to the latest version of iOS, which in this case would be 11. Once you do that, you can either set up the phone as a new iPhone or you can restore it from a backup. If you truly want to start from scratch, you manually download all your apps again and set everything up new. The big thing here is that you’ll lose all your old messages and health data, so if you want those, then the choice is pretty clear.
If you restore a backup, you’ll get all your old messages, health data, apps, downloaded music, photos if not using iCloud Photo library, etc. It’s worth noting that you’ll only get your health data back if you restore from an iCloud backup or from an encrypted iTunes backup.
Clean Install iOS 11
The first thing you’ll have to do is open iTunes on your PC or Mac. You can’t perform a clean install from the iPhone or iPad directly. From the device itself, you can only upgrade to the latest version of iOS.
Once you have iTunes open, connect your device and click on the phone or tablet icon that appears at the top.
This screen will give you basic information about your phone, such as the model, serial number, phone number and more. On the right, you’ll see the current version of iOS installed.
In my case, it’s version 10.3.3, which was the latest version before 11. If this is your first time connecting it, the message will say your iPhone software is up to date. Go ahead and click on the Check for Update button.
A message stating a new iPhone software version (11) is available should pop up. Here you want to click on Download Only. Do not click on Download and Update as that will simply update your phone to iOS 11 without formatting it.
Wait for the download to finish and then click on the Restore iPhone button. The other button should have changed to just Update rather than Check for Update.
If you haven’t backed up your phone yet, you will be asked if you want to back the settings on your phone or not before it restores the software. If you plan to restore your phone afterwards, make sure to choose Back Up.
After the backup or if you click Don’t Back Up, another message will appear asking you to confirm whether you want to restore and update. This means it will be restored to factory settings and the latest version of iOS will be installed.
When you click Restore and Update, an iPhone Software Update dialog will appear that shows you all the new features in iOS 11. Feel free to read that or save it if you like. Click Next and iTunes will either begin to download the update if you had clicked Cancel instead of Download Only in one of the earlier steps or it will begin the restore process.
You should also see on your phone that it says Restore in Progress. This will take some time, so feel free to leave it and come back later. Once the restore is complete, the screen on iTunes should change to the Welcome to Your New iPhone page.
It is at this point where you can choose one of the two paths that I had mentioned above. If you want the fastest possible device with the least bloat, you should choose Set up as new iPhone and download only the apps you need and set everything up from scratch. If you don’t want to spend all that time setting up everything again, then simply choose Restore from this backup and choose the backup you created right before the restore.
That’s about it. Both of these methods constitute a clean install because you are wiping the phone and installing a fresh copy of iOS 11. Even if you restore a backup after the fresh install, your phone still will run better than if you just upgraded directly to iOS 11 on your device. If you have any questions or run into any problems, feel free to post a comment here! Enjoy!
