Error 5 Access is Denied while backup database in MS SQL

Came across an error while taking backup of database in MS SQL Server 2008 R2

Error:
Unable to export database DB_MCMR_63: Cannot open backup device 'C:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\Backup\DB_MCMR_63FullBackUp.bak'. Operating system error5(Access is denied.).

To overcome the error follow one of the following three workarounds:

• Change the dump folder to a location where the SQL service have sufficient permissions to access it (e.g. a SQLDump subfolder in the SQL install location)

• Give the Network Service account read/write access to the specified dump folder.

• Another alternative is to change the SQL service Log On account to Local System or another account with access to the specified dump folder.