I have an older MacBook (as in, not the newest one, but the one before it, 160GB), and the only software update I need right now is OS X 10.5.7, and I've tried to install it a few times now. It takes hours, and it never finishes. It completes the first part, but after restarting, the loading/installing bar fills up a little less than a quarter, and stops there (it doesn't actually stop, it just hasn't gotten any farther, even when it's been installing for hours at a time). This is when it says "installing configuration," or something along the lines of it. Does anyone know how to fix this? Or does it really take this long? Or should I bring it in to a store? Thank you!