I presume you mean deleted DVDA entries in the registry (cleaned the registry, not deleted it). Make sure all folders with DVD Architect in the title are also deleted, including:
C:\docs & sets\all users\application data\sony\*
C:\docs & sets\<jjk>\application data\sony\*
C:\docs & sets\<jjk>\local settings\application data\sony\*
C:\program files\sony\*

Then when that doesn't work, restore your C: drive to before DVDA was first installed and reinstall DVDA and other apps as required.

The final act of desperation is to reformat your C: drive and reinstall everything.

I'll give it a shot.
JJK

I removed all files with the designations "DVD architect pro 52", "DVD architect", dvd architect pro", "dvdarch", "dvdarch52", "dvdarch50", "dar", and "dvdarch45" from the registry and the same thing happens. Downloaded 5.2 and retried and the same thing happens. I believe there is another entry somewhere without the dvd architect nomenclature. Somebody has to know what this is.
JJK

I want to go back to my first response.

Install disk??

I've been using SCS products since before it was Sony's product, and I've never seen instructions to remove the old before installing the new.

Where is the instruction to delete first coming from?

The downloaded version does the same thing as the disc, uninstall 5.2 first before re-installing. The reason I wanted to reinstall is that the DVD architect pro would not open. There was no uninstall in the program menu or in the programs in the control panel. It got blasted somehow but don't know how. All other Sony programs are just fine and I have all of them.
After I install the disc amd click on the install 5.2 (or EXE download file) it scans the computer and a menu pops up saying to uninstall 5.2 before re-installing 5.2.
JJK

"The downloaded version does the same thing as the disc, uninstall 5.2 first before re-installing"

I've installed Sony Vegas and DVDA through many upgrades, and reinstalled them a couple of times, and was *never* prompted to uninstall the prior installation or version.

Has anyone else seen the behavior that JJK is seeing?

Update:
I easily installed the old DVD A 4.5. Then tried 5.2 again and it would not install with the same problem-"un-install 5.2 before installing 5.2". Suspect there must be some tie-in with Vegas 10.
JJK

I have the same problem. Clicking on DVD 5.2 does nothing. So I thought I'd download and reinstall. When I run the downloaded install it tells me its allready installed and to uninstall 5.2 prior to reinstalling.

Problem is, Windows can't find it to uninstall it either!

I have decided to wait for Vegas Pro 10D update and see if that will knock something loose. Everything in the computer works perfect and I will not spend two weeks re-installing Windows Vista 64 bit to correct the problem. There is in my opinion one small line of registry stuff that should be deleted that I am not being told about.
JJK

Has there been any update on this issue? I'm running into the same problem; DVDA 5.2 won't open, I try to reinstall over the existing installation and get the "Uninstall before reinstalling" message. I can't find an uninstall app for it either though. Vegas Pro has one though...(???)

I have no idea if this will work but has anyone tried to download Revo Uninstaller Pro and see if it shows the uninstall app?

I installed the update DVD-A 5.2 build 133 and it went in slicker than camel snot on a doorknob. That's also with the "user account control" shut off.
JJK

So far I haven't seen any negatives for build 133. Touch wood!

I had ugliness this week with 5.0 & 5.2 too.
Leaving aside the reason (problem with 5.0), but I downloaded 5.2 as a trial. Ran the install - yes, go the message that uninstalling 5.0 was required.

Installed 5.2 & it didn't turn up in highlighted new programs, the folder was where it should be in Program Files with bits & pieces, but no executable to click on & no icon on the desktop. Eventually, I went to Control Panel, uninstalled 5.2 & put 5.0 back & updated it to a higher build number. The original problem with 5.0 that prompted trying 5.2 was solved with that, but now I have another problem - but not for this thread.

What build of 5.2 did you have trouble with?

Build 156.