Windows 10: how to remove strange clear rectangle?

a transparent rectangle has appeared on my screen after my cat walked over the keyboard, i cant get rid of it and idk what it is

:)

 

Strange Grey Rectangles on Screen

Since over a week I have been dealing with three strange rectangles on my display. They appear already on system start up before the log in screen. I tried to find a process on Task Manager that may cause this annoyance. I remember having installed a Windows
store app, Ditto. I uninstalled it and rebooted but still there Those pesky rectangles appear in normal and safe mode and in any account. Below are 2 pictures to show what I'm talking about. Any help greatly appreciated � 3 annoying rectangles on Log-in
screen Even in Safe Mode, those 3 annoying rectangles won't go

 

Clear Pagefile on Shutdown


I've been looking into clearing the pagefile, and I found the following steps at a somewhat dated webpage:

1. In the registry editor, navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
2. Set ClearPageFileAtShutdown to the REG_DWORD value of 1.
3. Restart Windows.

I'm just wondering whether those steps are still valid, and, if so, does clearing the pagefile work as advertised?

 

Clear "Pin suggested" list in People Bar

Does anybody know how to clear the "Pin suggested" list on the "People bar"?

Contacts are added to the "Pin suggested" list once you've pinned and unpinned them. But there seems to be no obvious way to remove them from that list.

After playing around with this feature and pinning and unpinning many dummy contacts, it's rather annoying to see them in the "Pin suggested" list when you click on the "My People" icon in the taskbar.