I upgraded my Toshiba 1640 laptop from W98SE to WXPP SP1. This laptop has a K6-2+ @ 475 MHz. The version of W98SE provided by Toshiba did not support PowerNow but I can adjust the clock speed / multiplier using e.g. CPUID. This setting survives a hot boot so I assume the motherboard does support PowerNow. WXP supports PowerNow but unfortunately SP1 needs a fix to be downloaded from Microsoft. This fix (Q306458_WxP_SP1_x86_enu.exe) contains a driver: AMDK7.SYS.
The question is can I use this driver for my K6-2+ ? Windows will allow it but advises against it.