PostgreSql Startup Error

Hi Team;

I am unable to start my PostgreSQL Server.

When I try to start the service I am getting the error below;

System Error 5 has occurred

Access Denied

Where could I be going wrong because it has happened to me more than one time and what I do is to reinstall PSQL a fresh.

I need a long lasting solution so that I do not need to reinstall every now and then.

I am running on windows 7

Kindly assist.

Regards;
Brian