Pretty weird. The upgrade wouldn't install for me even though I'd just installed my newly rediscovered flip hair version 1, (same reason outlined above). Then I remembered that I had an old Poser4 folder copied over from my previous computer. The flip hair was installed on that, so just for a laugh I thought I'd try and do the upgrade in there. And it worked! Now this is the same flip hair installed from the same exe file (I only ever had the one). The files read the same size down to the last byte. So I copied them into my newer Poser4 Zygote hair geometries folder, and sure enough Windows asked me whether I wanted to replace the existing files. I did so, and then the upgrade went ahead just fine. The only difference I can see is that the files from the old install of version1 give a 'modified' time of 01:00 (12/04/2000), whereas the files from the recent install of version1 (same exe file) give a 'modified' time of 00:00 (12/04/2000). Anyways, for whatever reason I can play now. If you have an older runtime with the flip hair in it, you could try this too. UPDATE: It appears that it IS the time on the file that is causing the problem. Subsequent to writing the above I started from scratch again but used a file properties changing utility and adjusted the time from 00:00 to 01:00 on the blMWFlipHair.obj file. After that the upgrade went ahead just fine. I can change the file properties from within my "PoserDesk" file utility (way better than Windows Explorer), but if you don't have that there are utilities available on the net. There's a shareware (with nags) here: http://www.segobit.com/fpc.htm I hope this helps someone(s).