I recently got my grandpa's old iMac from 2006. I made my account, made it an admin, and deleted his. I put 10.5.1 on it since it had 10.4 before. Now when I try to get the update, it says I don't have sufficient privileges. I don't know why this would be. I have 512Mb ram if that has anything to do with it. I'm also having other issues with privileges, like writing to and partitioning my external hard drive.