Upgrade TS8.0 to TS8.1 Problem

[Mike Symth <mqsymth@xxxxxxxxx>]

I have TS8.0 build 1869 and TS2000i on my computer.  My computer has
WinXP Pro SP2, 1gig memory and an AMD 2100.

 I also have a D:drive that is an exact mirror of the C: drive.

 When I first attempted to upgrade to TS8.1 build2821 it trashed my
8.0 wrk file so it would not work and then gave me the error " unable
to determine the version of your workarea".  The D: backup did not
restore 8.0.  A call to TS support and an hour on the phone with them
finally put 8.0 back although I had to redownload all the chart data
prices again.

 Another call to TS support suggested that since I had a backup to 8.0
that  I should uninstall  8.0 and then download and install 8.1. In
addition they had me download and install msicuu2.exe and delete all
the TS8.0 lines found in running that app.  Also that had me download
and run a TSreg.reg that deleted a number of TS registry items. All
this  did not work and the install of 8.1 gave me the error 
"tsinst10.exe not found in C:\program files\common files\tradestation
technologies\tradestation setup is aborting' .  In checking, the
tsinst10 file was there although it had the file date of 9/10/04. 
Next support suggested that I delete that directory and rename the
tst8.0 directories on my D: drive.  I did that but encountered same
error on the 8.1 install. Next I searched my registry and found 20 or
so 8.0 references. Support suggested that I delete all those registry
items that had TS8.0 in them and try again. I did that but encountered
the same 8.1 install error.  Next I moved the tsinst10 directory that
is on my laptop that has 8.1 build2706 to my desktop in the correct
directory position.  On install of 8.1 I encountered the same tsinst10
error.

 Next support said that I had to backup and uninstall TS2000i and all
it's registry references and take my D: drive offline.  this is where
I gave up because this was ridiculous!  I then did a restore to a date
that 8.0 was running and put my system back to the state before the
upgrade to 8.1 attempt.

 As a note, last year when I upgraded from ts7.2 to 8.0 and then to
higher builds of 8.0, I had absolutely no upgrade problems.  The only
thing that has really changed since the last TS upgrade is the WinXP
Pro SP2 upgrade.

 Has anyone else encountered this problem? Does anyone have a solution?

 Thanks for any help!