Hi Anil Kumar M R,
Based up on your query This issue can be cause due to the display settings on the RDP client, due to a slow network issue or low space in C:/ drive. If do you have any other VM please try to login if the same issue persists there will be the issue RDP setting might be.!
Please check the suggestions provided in the following threads along with Microsoft's official documentation on this.
https://stackoverflow.com/questions/38581928/azure-windows-vm-shows-full-black-screen-in-rdp
If you are still facing any issue, please let us know in the comments. We are glad to help you.
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Thank you.