Hello Rashmika,
Initially there is no Windows Insider Support. You must use self-help support, meaning that you sink or swim using resources such as articles, books, forums, experience, friends, help files, etc. That is an important reason not to use previews on primary or production devices. The Windows Insider builds or Technical Previews are released as is, for testing purposes but they lack the most resilience fixes of the Release versions
I would suggest you to try the next actions:
Power on your computer and power it off as soon as you see the Windows logo. Do it three times.
After the third time, Windows 10 will boot into diagnostics mode. Sometimes holding the Shift key while booting will bring up this screen. Click Advanced options when the recovery screen appears.
Select Troubleshoot > Advanced options > Startup Repair.
If the issue persists, proceed with these steps:
Select Troubleshoot > Advanced options > Command Prompt. When the Command Prompt window appears, enter the following lines and press Enter after each line.
bootrec.exe /rebuildbcd
bootrec.exe /fixmbr
bootrec.exe /fixboot
If you are considering going back to Release version. In order to do a total clean install you will require an 8GB flash card, download Media Creation Tool to create a bootable flash card.
https://www.microsoft.com/en-us/software-download/windows10
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