Mac mini upgrade

Soon wanted to upgrade my mac mini from 512mb to something higher. Bought 1gb memory. Made upgrade. Turned it on and on starting got flashing folder with question mark. First though was that os is just not identified. Tried to make all process from begining. Does not helped. Tried to add the old one memory. The same error appeared.

After two days of opening and closing case I decided to try plug out hard drive and plug it in again. And it helped. And how fast bacame make. Please to work. Photoshop starts in few seconds. I am thinking about upgrade to 2gb. Upgrade mac is very easy. Even hard drive can be upgraded in 5 minutes. Just when you get all things together, don`t forget to connect all necessary wires. Becouse one time I forgot about one wire and when I turned mac on I heard terrible sound of working fan.