Adobe 9.1 Question

[RTSDaddy2]

My sister's boss was trying to run this when it came up with a registry key error, in which it said HKEY Local Machine\Microsoft\Windows\Run\Optional Components\MSFS key was not working or on; I checked for it, but did not find it in his registry. He's already using Adobe Reader 5.0, so we know that - at least to a point - adobe will run on his machine.

My question. He's running XP Service Pack 2, and has more than enough ram and disc space to accomodate that program. Any ideas as to why the install would stop there and uninstall everything, and how can we get around it - or can we?

I'm going back and check the specs for 9.1 myself - don't know why this is happening right now, but maybe I missed something.