Can I insert a new (larger) harddrive into a Maxtor OneTouch case?

The Maxtor One Touch was introduced in September 2007, it should still be under warranty. Hope you saved the receipt! If not, send it in to Maxtor anyway. They’ll repair it for a fee. Did you drop it? Seagate usually makes good products.

There were OneTouch models available before 2007. And, on a more responsive note, yes, you should be able to use pretty much any IDE drive as a replacement mechanism. I personally prefer Seagate and Western Digital, but anything should work, assuming Maxtor didn’t do something funny with the controller firmware to lock it to, say, Maxtor mechanisms. They’re not bad, either, really. Maybe just to be on the safe side, drop in a Maxtor as the replacement.