My Powerbook G4, running 10.4.8, was slowing down and I was having problems with Safari. Also, trying to run Software Update wasn't working. It would just sit there searching, never find anything. And I couldn't download Safari upgrades, OSX upgrades, etc. When I tried to run he Techtool program that came with Apple Care, I couldn't get the computer to boot off the disk. Just gave me a blue screen. SO...I thought I would do an install and archive, but in a stupid move I accidentally used the 10.3 disk the computer came with instead of the 10.4 disk, and did and install before I realized what I was doing. Now it boots up, but when it takes me to the login page, it won't recognize my passwords. Any advice? I'm trying to avoid wiping it clean and re-installing everything. I have a lot of programs and half the disks are in storage somewhere. Also, any ideas why the computer may have be slowing down before? I tried disk utility and it said the hardware was fine.