To those of you who've been having the same problem as me (TWEE installer hanging for hours on end at the 'modifying game files' message), I may have discovered a solution!! --I did two things differently, this time around. (1) I made sure that my re-installed .Net Framework had only been updated to 3.0, and NOT to 3.0 SP1. (To fix this, I uninstalled both 3.0 SP1 and 3.0 itself, and then re-installed 3.0 using the full Microsoft .Net Framework 3.0 Redistributable package --> http://www.microsoft.com/downloads/details.aspx?FamilyID=10cc340b-f857-4a14-83f5-25634c3bf043&DisplayLang=en(2) I did not allow the base TWEE installer (TWEE_Update.exe) to install the extra add-on adventures (Price_of_Neutrality and Side_Effects), but instead decided to wait and manually install them afterwards, if all went well.This time around, after the fresh .Net Framework 3.0 installation, the TWEE installation actually went ahead without a hitch. More specifically, instead of coming to the "modifying game files" message and then having my hard-drive activity CEASE, the hard drive was instead going crazy with activity the entire time through the process (which was a sure sign that I'd accomplished something, at least!). After about 35 minutes, it gave me the thumbs-up on a successful TWEE installation!!!!I did have some issues getting the game started -- had to lower my sound hardware acceleration (as I have a Creative Audigy card), but I did get the game up and running eventually, and it's looking great so far! I also ran both the Price_of_Neutrality and Side_Effects installers manually, without a hitch. As far as I can tell, my problem's solved!I do hope these tips work out for some of the rest of you who've been having this trouble. Post here and let me know! All the best,RoA