reg:Installation problem on windows

Hi all,

  When i am trying to install postgres 8.1.4 on my window system i am facing problems....I am getting the following errors.Please suggest me how can i overcome this and install successfully.

 

->Internal account lookup failure:Mo mapping between  account names and security IDs was done.

->Failed to create process for initdb:Logon failure:the user has not been granted the requested logon type at this computer.

 

Thank you,

Sandhya