Complete with the 3k memory expansion, bringing the memory up to 8k. I also have hte tape drive. Haven't tried recently, but there's no reason it couldn't run.
The oldest PC I could get running is a 386SX. Don't know if the hard drive has survived, though. I can replace it.
The oldest system easily running is a P166 with Windows95.
The oldest system currently in use is a 2001 system with XP. It's a garage/shop system.
I also have a collection of 2000-2006 parts and hardware. I might be able to build another working system or two out of that pile. If anyone wants to pay shipping from Texas, the parts are free for the taking. No guarantee anything works, though.