Massive app crashes, phone unusable

Hi,
My girlfriend has the moto g and since this morning it's unusable: every second comes a crash message that a app fc. All apps belonging to Google (YouTube, calendar...) are crashing and especially the launcher. It's just possible to go to settings via quick toggles. But I can't delete any data etc from apps. And it won't accept any changes to any settings. I can't open any app because the launcher doesn't work...
The problem: it's an unrooted, totally stock phone with just a few apps (whatsapp, chronus...) . Now I wanted to ask if anyone can help and maybe knows this problem and how to fix it. And: I can't connect it to the PC (win7). Anyone has a link and a description to install the USB drivers? I tried all the "normal" ways with Motorola device manager and manually install USB drivers. I want to backup the messages and pictures before I try a factory reset. I rebooted it in secure mode, but all the problems still exist...

I hope anyone can help... Thanks in advance!

alikpronoy said:

If it always crashes how would you be able to back up SMS and picture? Try to go to the store you bought your phone or call your tech support. But if nothing happens you just need to factory reset your phone.

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If it connects to the pc, you can easily make a backup of these things. The Problem is that it doesn't connect because i have problems finding the correct usb driver.

alikpronoy said:

As much as we want to, but I think, there's no way to back it up. You just need to factory reset it.

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Already tried a factory reset - doesn't work. Can't even boot into recovery... Now it's sent back to Motorola I would love to know what happened there on a complete stock phone with just a very few apps and just used for messaging, calls and photos. I hope Motorola says what went wrong when the phone is repaired.