A common mark indicating that a Windows peripheral device is not installed properly is a yellow triangle icon with an exclamation point in the Device Manager. This symbol signifies that the device has encountered an error or that the drivers are missing or incompatible. Additionally, the device may not function correctly or at all, prompting troubleshooting steps to resolve the issue.
the Device Manager
peripheral
a device driver
If you can not view your webcam, it may be because its software drivers are not properly installed. You can check their status/re-install them using Windows Device Manager.
Like regular device drivers, peripheral device drivers should be updated from time to time. Updates ensure that your device is patched with the latest updates, fixes, and enhancements. You can update your peripheral device drivers in several ways including by using Windows Update or going directly to the device manufacturer's website and downloading them there.
I don't know about three things. But it can be because of many different reasons. First, the device doesn't work properly; second, the user remove drivers; third, bug in the software and so on. If device is working properly, what you can do is turn everything off. Then start the pc, wait while it's booting up. After you logged on and windows started turn your device. If nothing was broken it will work again.
Depending on your device, device drivers are either automatically installed by Windows, or manually updated by the user.
External Devices
System Restore.
What interface that controls a peripheral device is.
System Restore
yes, pen-drive is a peripheral device.