[Metacard] Win XP: a new dawn

[Dave Cragg]

Hi all

Be warned!  The new dawn is what you'll see after working all night 
to see if your old apps still run on XP. :)

First, Metacard seems to run fine. I've had no "engine trouble" so 
far. But XP's new security enforcement may catch you out. (It caught 
me out.)

Two main problems so far: running an installer and writing files to 
places you shouldn't.

But there's an extra twist. If you install XP over a previous OS (NT 
for exmple) it retains the basic security setup of the old OS. This 
is what I did at first, and everything seemed to run as before. I 
told my client that it performs fine under XP (we'd had a report of a 
user not being able to run the app with XP), and he went away happy.

A day later, I re-installed XP following some hardware problems. This 
time I made a clean install. I tried to run the client's app again, 
and things were different. After starting the installer ( older 
version of Wise), I was greeted with a very pretty system message 
that an Administrator password should be used to install applications 
(I was logged in as a plain user). But it gave the option to install 
under the current user account. I tried with the user account, and 
the installer failed with an error about access restrictions. I'm 
guessing it was when writing to the registry.

I installed again, this time giving an Administrator password, and it 
installed fine. But when I ran the installed app from the user 
account, I immediately hit problems. The app writes a file locally in 
the same directory where the standalone is. This is mainly 
configuration data, and I think a number of users on the list use 
this technique. Anyway, this was a no-no. No writing to the Program 
Files directory for plain users.

However, I found that by copying the complete directory that contains 
the standalone and other stacks out of the Program Files directory, 
it would run fine.

I'm now trying to work out what you can and can't do, and also find a 
better strategy for running and deploying the application. But I 
can't find any clear documentation on this, only a number of 
references to thing being different depending on environment: XP 
Home, XP Pro, installed on a workgroup network, installed on a 
domain, etc. So far, it looks like security through obscurity to me, 
but I guess there's a method to it. If someone knows a good reference 
for this, could you let us know.


Cheers

Dave Cragg