I kinda' went through all this when 2.42 came out, after several tries & downloads it still would not work properly in my machine. very slow & clunky. I asked at the "blender artist forum" [elysiun]. not much help. [I guess they meant well but no answers that I understood] so I left it at that. I past up 2.43, now I try 2.44 w/ the microsoft download etc. it would not really open. I have 2.41, aside from it won't invert zoom,[very annoying after so many yrs.] it works, but it doesn't do bump map stuff like the optimized 2.37a that I use. I'm not very good w/ all this tech stuff, I'm just an old artist that has been enjoying blender for about 5 yrs.  It was always a simple download & worked fine right off. I'm gonna continue to use & enjoy my 2.37.
   my machine is about 2 yrs old w/ the current set-up....XP professional...AMD 64  3200cpu....2gig of ram. I had this machine built to play w/ my blender animations & it does fine. I would love to try some of the new stuff.  I've considered getting a new machine built but at this point I'd be afraid I'll lose what I have working now.  any help would be greatly appreciated, but please don't go too techno on me. like I said I'm just an old artist......thanx.......johnd