I rebooted the router and modem today. PC has acted a little funny lately.
Sometimes I get a msg that says something like :

There is no disk in drive D. Please insert a disk into drive D.

cancel........Try Again......... Continue

buttons. And the buttons will not work. It makes a beep noise.
This message will pop up for various applications for some reason.
Today in Notepad I tried to save a file to my desktop and this message wouldn't let me, and Notepad seems very slow and doesn't want to respond.
Do you have any idea what's up?

I haven't defragmented in a long time because my main HD is a solid state and supposedly doesn't need it.
I ran Spybot last night.

This message also wouldn't let me run Glary Utilities a week or so ago. It asked for me to insert a disk into drive D.
I don't even think I have a drive D. I use USB card readers often.

TIA. Lurch