Both have played Starcraft 2 (since launch) and D3 (since launch) with no problems.
On my old system, when 1.0.7 went live, the Blizzard updater (not the D3 launcher) stuck at around 60% - I fixed this myself by simply launching Starcraft 2 and it patched up - then I was able to launch D3 successfully.
Now, still on my old system, with the small 22.214.171.12433 update, it's doing this again (Blizz updater stuck at around 60% again NOT the D3 launcher but the Blizz Updater) but this time the Blizz updater is getting stuck with Starcraft 2 as well (not the SC laucnher - but the Blizz updater).
My new system opens both D3 and SC2 with no problems - but is there any way I can get D3 working again on my old system which has been playing D3 fine since May 15th 2012 until these last few patches?
Assistance would be appreciated.
EDIT: Looks like my Blizzard Updater files were possibly corrupted after the recent 126.96.36.19933 update which causes the updater to stick at around 60% for both SC2 and D3. I followed the sticky instructions at the top of this forum for patch looping here: http://us.battle.net/d3/en/forum/topic/7414952171
After copying/pasting the files to the propper places I was able to start D3 on my older system (XP) again - hopfully this will STICK and if I run into this again maybe that will continue to fix it.
An error msg concerning corrupt Blizzard launcher files would be nice when this happens so people don't have to reach around in the dark trying to guess what's wrong ya know?
Until next time I'm calling this resolved - hope this works for others!