I tried as above mentioned & nothing is working, stilli am getting same error even though i am only one connected with SA priviledge.

i did what you mentioned about to SET Multi_User & still getting same error. any help will be appreciated.

I tried that option & still same error.

Alter Database CCS_SITE_Monthly

SET SINGLE_USER

With ROLLBACK IMMEDIATE

restore database CCS_SITE_Monthly

from disk = 'E:\Temp\CCS_Site.bak'

with replace