Install MS where ever you like. (I have never really had a good attempt at installing MS on a thumb drive, but I don't see too many reasons why it wouldn't work?).
MS doesn't really care where the data files are located (although closer is faster!) All add-ins must reside in the External Function DLLs folder in the installation folder of MS.
wabbit
"The question of whether a computer can think is no more interesting than the question of whether a submarine can swim."
Edsgar W. Dijkstra
MS: 6.52 EOD, 7.x EOD, 8.0 PRO, 9.2 PRO w/QC, 10 PRO w/QC C, 11 PRO w/QC & MDK
For custom MetaStock programming : http://www.wabbit.com.au
My SkyPE status : 
My SkyPE account : wabbit.com.au