Sql Server Installation On Windows 8 Laptop

Hi Al,,,
Iam Installing Sql Server 2008 R2 in Windows 8 Laptop...


In the end of The Installation it Showing that "Accont is not Valid or You Dnt have Permissions " ...


Why This Problem is coming and What I should Do to install it successfully...??


Thanks In Advance,
Sathish Pabbathi.