Jan Steunebrink has a patched BIOS for that board with large hard drive support. http://web.inter.nl.net/hcc/J.Steunebrink/k6plus.htm

Long term storage in anything other than an anti static bag means a very good chance of ESD damage that can render sensitive electronics useless.

A couple of screen shots.

I just threw together an old system over the weekend just for fun: a DFI K6VB3+, a K6-2+ 450 @600 (2.1 volts) a WD 40 gigabyte HD on a Maxtor/Promise ATA 133 drive card, 640 megabytes of PC133, a Philips PSC706 sound card, and a GF4 Ti 64 megabyte video card in an AT case. I installed XP pro - it …

I guess I have it's been many years since I messed with those chips I have a K6-III 450 running in a 430TX board at 400mhz... it'll never be as fast as a Super7 board, but it's damned reliable at least! There is a very good chance that you could run it at 450, or even 500 MHz in that board if you …