Hi Sameer,
please, a subject should be short and clear, it's not the place where the whole question should be written.
I agree with Andrew it's probably caused by graphic driver, these problems were discussed in several times in the past. For better understanding of your situation, you should share at least:
Check the links provided by Andrew, they contain more information how this issue can be solved.
With regards,
Jan
Bentley Accredited Developer: iTwin Platform - AssociateLabyrinth Technology | dev.notes() | cad.point