Two ways to transfer iPhone videos to PC
There are two ways to do that:
First, connect iPhone and PC, then select the device under "My computer" - "Devices and drives". There in the folder, you can find iPhone photos and videos. Sad thing is it will not seperate photos and videos, so you may have to check the "Property" to get the right ones you want.
The other way is transfer app, the one I'm using is ***. Of course, there are many other transfer apps in app store.
I've done this, not recommended, not support ios 8.
If you meant to do so, follow these steps:
1. Connect your iOS device to your computer. If the AutoPlay window appears, click "Import Pictures and Videos using Windows," then skip to step 4. If the "Import Pictures and Video" dialog appears, skip to step 4. If the AutoPlay dialog doesn't appear, you might need to check your settings.
2. Choose Start > Computer.
3. Right-click the logo for your device and click "Import pictures and videos."
4. Click Import Settings.
5. Click the Browse button by the "Import to" field and choose where to import your Camera Roll's photos. By default, these will import to the My Pictures folder.
6. Select "Always erase from device after copying."
If you delete photos after you import them, you can reduce the size of your Camera Roll and improve backup and restore times.
If you want to import the photos to additional computers, don't select this option.
If you don't want Windows to delete photos from your camera on subsequent imports, remember to come back here and deselect this option when you're finished.
7. After setting your import options, click OK to dismiss the window.
8. Choose a tag, if desired, and click Import. This screen appears only while the import process is active.
9. After the import is complete, Windows Photo Gallery will show your photos and videos in Recently Imported.
If some of your photos didn't import from your device's Camera Roll, you can copy the photos to your computer using Windows Explorer or import the photos using software such as Windows Live Photo Gallery or Adobe Photoshop Elements 3.0 or later.
This official guide is also working:
How to Transfer Videos from iPhone to PC