Error When Login

Dear CS Cart Admin

i am facing problem my store was working fine yesterday, today when i login i recieve a message

Access Denied

i am totally unable to login my admin panal, my other accounts are working fine like Vendor and customer but i cant login as admin

i have tried to reset password but noting

same error i found.

i think last day i have made some changes, my admin user is gmail accont but when we send mail vendor that was show gmail so i made some changes like no-rep@domain.com

its working good but i dont know what happen kindly guide me what i do now?

i am waiting for your reply..