MacBook Pro mid-2008 freezes or causes file system problem I have an old MacBook Pro (mid-2008, 15 inch). Apple replaced the main board and I upgraded RAM and replaced HDD.

When I use OSX on it, it freezes randomly and I have to reboot it.

I installed Ubuntu on it, it never freezes but sometimes it hangs for a while. And the other day, I copied many files to it over from network and the files are set read-only mode. I can't delete them even with sudo.

When I use the MacBook, usually it's very hot.

It might be too old to be useful now. However, I like it very much especially the keyboard (the metal one).

What do you think cause the problem? Is there a cheap way to diagnose it to find the problem part? I wouldn't mind spending 100 bucks to revive it.
It sounds like you might have faulty RAM. your macbook is not too old. I still use my white macbook from early 2008 with a hacked version of ML (not supported by hardware) with no issues. Try Memtest http://memtestosx.org/