With SMC I discovered that if I installed the Klite codec pack and the Qtime “Qlite280” pack from Klite site ,that I could convert video easily.
BUT
If I then unistalled both packs … and heres the good bit… I could still convert video flawlessly…
Without either of these packs installed SMC either refused to convert or crashed ,never crashed Vista completely tho.
Strange but true.
Hope it helps.