Hello Srijith. I'm Greg, 10 years awarded Windows MVP, specializing in Installation, Performance, Troubleshooting and Activation, here to help you.
Try these fixes to repair or reinstall Windows Powershell 5.1:
https://windowsreport.com/windows-powershell-st... (Avoid ad links which intrude into editorial copy, especially avoid Restoro, PC Repair Tool and Reimage ads)
UNINSTALL: https://www.thewindowsclub.com/how-to-uninstall... (Avoid ad links which intrude into editorial copy, especially avoid Restoro, PC Repair Tool and Reimage ads)
REINSTALL: https://docs.microsoft.com/en-us/skypeforbusine...
https://www.reddit.com/r/PowerShell/comments/ig...
https://www.addictivetips.com/windows-tips/how-...
If none of that works you can try to upgrade to 7.1:
https://4sysops.com/archives/how-to-install-and...
I hope it helps to have all options. Feel free to ask back any questions and I will be here to help.
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