I recently installed a new hard drive into my Power Mac and I installed the Mac OS X 10.4 software. After the download, the computer restarted and after it restarted, the Apple Logo appeared and some type of spinning circle (Circle made up of lines) stared to spin. I also replaced the battery inside and hit the reset button. The funny thing is, the computer was working fine yesterday. The circle has been spinning for a couple of hours now. What can I do? I am open to any sugestions.