DVRMSToolbox can definitely convert dvr-ms files to mpeg2.
I am using it on win7 x64, every now and again though I do get an odd recording that won't convert at all - I assume it's due to corruption during the recording.
Rob.
Win7, P5Q Pro Turbo, Q6600, GT430, BGT3595, Hauppauge Nova-hd-s2, DM500s, DVBLink.
www.thegreenbutton.tv
I've had scattered luck using a different preset within DVRMSToolbox.
There are two presets for converting DVR-MS to MPG, and I've found the one called "DVR-MS to MPEG with ffmpeg" can sometimes do things the other one can't ("Convert DVR-MS file to MPEG").
Emphasis on "sometimes".