I've been using Ardino on windows XP for many years. Done updates many times, several machines. On the machine I was using this morning, not my oldest, I can see the backups going back to at least 0017.
Never particularly had trouble with updates...
So it was a nasty surprise this morning to have no end of hassle with an attempt to upgrade from 1.0.6 to the "standard" version presented to me by download page 15 Aug 2015, 1.6.5-r2
Normally, I just rename the old C:/Program Files/Arduino folder, to hide it from the installer. Had trouble even doing that, because I left it a little too long. Luckily, by then I was suspecting the updater of "being clever", and renamed it AND copied it.
Finally got the "update" to work... and found that I had a "new install" of 1.0.6???!!! NOT installed in C;/Program Files/Arduino, which was free at the time install invoked, but over the top of what was supposed to be my backup, Arduino-1-0-6... or so it seemed to my by now much confused self. And I have enough experience that it takes a bit to confuse me.
Is 1.6.5 not XP compatible? If the installer called 1.6.5 is only going to give me 1.0.6, it ought to say so.
Questions: Will 1.6.5 run on XP? (Apologies if RTFM would have answered that)
Is it "normal" that running the 1.6.5 installer would install a 1.0.6 version?
Not a happy camper. Sigh. Will be less quick to do an update in future!