I have an upgrade package to Ultimate.
Before I install it, need to know if I will have to reinstall all my
programs on the computer.
Does the upgrade package delete all other programs installed or just the
OS
and still have your programs work as before.
Here is my 2 cents worth:
An upgrade overwrites the OS files, but not any non-OS files, unless those
non-OS files happen to be in the same folder and have the same name as some
file in the new OS. This is one way that a new OS can break an old program;
the old program was badly written or installed badly, in a place that the
new OS would overwrite it. Seven years ago Microsoft put out guidelines
that software/hardware vendors should follow in order to minimize conflicts.
Some software/hardware vendors are only now getting around to putting out
software that follows these guidelines.
The installation process also goes through the old registry, looking for
references to non-OS stuff (your old installed software), and attempts to
put equivalent entries in the new registry (without these registry entries,
the old software can't run). If any of those old installed software
packages are not compliant with the new OS, they may not run, or they may
run fine (and not interfere with anything else) or they may run fine but
screw up the OS so nothing else runs properly, or who knows what?!
The installation process also has to do something with all the old drivers
and update what it can to drivers compatible with the new OS. I'm sure
badly written old drivers can screw up this process too, in many different
ways, with no easy way to trace the symptoms back to the cause.
I think your best bet is to plan for the worst and hope for the best. The
best would be doing an upgrade install and everything runs perfectly. The
worst would be removing/disabling all non-essential hardware and doing a
custom-clean install, and then methodically adding optional hardware and
your sofware to make the computer useful to you.
You should run Microsoft's upgrade advisor that tries to flag
incompatibilities. Note that it is only an advisor and can not be
all-knowing.
-Paul Randall