Weirdest thing I had Acrobat 8.3 Pro pinned to my start menu and one day when trying to open it wanted to install. I let it go through the process but it ended with the attach. Same thing happens from the program menu.
However, if I click on a PDF and open it that way everything in the program works fine.
I seldom if ever have to use a start button but would still like to know what's going on.
I'd try to repair but have CS3 and shutter at the thought the rest of the suite get screwed up trying to repair Acrobat.
On a somewhat related note about the same time the start button started malfunction, PDF icons were no longer in preview mode but default icons. So I had some with previews and newer ones with the default. I got around this behaviour somewhat by making Nitro my default viewer which immediately showed the preview icons and then switching back to Adobe.
PS there's a folder with the same name minus \data1.cab in the set up folder