Weird repetitive address bar drop down

[account_disabled]

I am using Windows 8.1 on my laptop. From the past few days I am facing this weird issue of address bar dropping down again and again in folder view. It does not stop. It appears as if like a key is pressed down and stuck but I checked that there's no such case. This drop down menu keeps dropping down in the "Open file" dialogue box in all software. It also keeps drops down repeatedly in the Run menu of windows.

Another issue is, while browsing from chrome or firefox, the tab gets closed suddenly.

I scanned my system with antivirus and did not find any viruses. What should I do?

Please help.

Thanks!

I didn't find the right solution from the Internet.

References www.techsupportforum.com/forums/f320/weird-repetitive-address-bar-drop-down-1205281.html

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