#1- rebooting is slow
That can be a ton of different things. Such as how many things are running in the background? They have to all be shut down, and drivers as well, a lot of time when shutdown gets stuck it is because a driver isnt unloading. This can also be true if a driver is taking for ever to unload. So number of programs and services running and drivers are the trick there.
2- when using administrator to run programs screen flickers.
That could be a video driver issues, perhaps even the cause of #1 as well
Download newer drivers, uninstall the old ones, reboot and then install the new ones.
3- recycle bin just hangs, and finally windows defender gives an error # OX800705b4.
Go tot he Windows defender folder and take a screen shot of the files int he folder for me and post it.
Shane