OK folks I have verified that this fix works for some people. This reg key is installed by windows and activation uses it during hardware ID calculation. It is not meant to be changed by 3rd party software, but it appears there are a few apps out there that do just that.

I looked up in my MSDN documentation how to write a filter driver and it is perfectly valid to update that registry key and add your filter driver to it. I did a few experiments. I looked up information on what Acronis does and I saw that they just append to that key, so on my system that means PartMgr wasn't there.If I switched it back to "snapman", then Acronis worked, but FSX would ask for me to activate again. If I put it back to PartMgr, then FSX would startup without asking about activation, and Acronis would say that it couldn't find any hard disks (not a message I liked seeing). I uninstalled Acronis True Image and re-installed. This time when I looked at the Upperfilter key, it contained "PartMgr snapman". Both FSX and Acronis True Image then worked fine.So the mystery to me is, if FSX is dependent on PartMgr being there, why wasn't it there on our systems?Also in the future, if PartMgr gets removed then FSX won't startup without asking for you to activate.Bruce

I was curious and took a look at my registry. I once installed Acronis for trial, but deleted it after the 15 days or whatever. (For me, both Acronis and Ghost do too much low-level stuff for me to trust.)Here is a key I found:UpperFilters PartMgrUpperFilters.bak PartMgr snapmanDo those two entries for .bak mean 2 different backup values, or entered in the same key?scott s..

Here is a key I found:UpperFilters PartMgrUpperFilters.bak PartMgr snapmanDo those two entries for .bak mean 2 different backup values, or entered in the same key? Does anybody have any insight on what Scott has said here. I also have the upperfilter.bak, but mines blank same as the upperfilters was. I'm just wondering what the bak file is.Thanks, Dan

Hi,I had the activation problem too.After "exploration" inside the system (catching of registry events),I found, that msxml3 (MS XML parser) is necessary for correct connection to activation server.(http://msdn.microsoft.com/XML/XMLDownloads/)When I installed this version, activation was without problems.(Note, that xml parser version 2, 4, 6 was on my machine before it...)Maybe my solution will help somebody.Cyro

I would guess that when Acronis installed it backed up the original value and then when it uninstalled it put the bck version back and made the one it had updated the bck version. "PartMgr snapman" is the way it should be when Acronis is installed.Bruce

Hopefully something like this will come along for the install problem. I tried it anyways but no luck.