ok, not sure if this will help your issue exactly but it might so i am posting it here. i had a similar issue, where iTunes would actually install but then crash on startupy. I thought it might be a file that was corrupting the process because there was no eorro log or information from Apple. (NOTE: I also tried to install a previous version of iTunes but that h did not work because the library (.itl) was related to the more recent version so that did not fix the issue for me and that might actually work for you since you can't even install the latest version.)
I went to my start menu and looked for any all podcasts, thinking that delieing all my podcasts would be the easiest thing to do becuase they can be so easily recovered. This actually fixed the problem. I think i had a podcast that was corrupted and crashing my iTunes on startup.
--start menu> search> type in ".mp3"
--when all your .mp3 fils come up in a file window there will be a search box in the upper right hand corner.
--type in "podcast"
hope that works.