For over a year I have not been able to install sqlserver on my system. I spent months and 70+ hours trying to fix this to no avail. It started with SCCM; after uninstalling it improperly I was left with junk in the system, and no longer able to install
subsequent installations of sql. Even after dist-upgrades, given there are over 11,000 registry keys buried in the system, its hard to clean up. I just fixed my problem and managed to install it for the first time in a year. Simple process... you will need
two things. Windows Installer Clean up, (I just found out now a new one
was released last month, but I used the
old one and it worked successfully) and at least "Revo Uninstaller 4.0." There are multiple approaches. My version Microsoft SQL 2008 Server Express Edition.
Here is how I did it!
1. I tried to install it, it failed.
2. Before closing/rolling back installation, I opened "Windows Installer Clean up" to confirm installation entries had been reported. They were there. Seeing that SQL uninstaller doesn't do its job right, Iopen task manager and kill the setup-installer rather than letting it roll itself back.
3. I opened revo-uninstaller, highlighted SQL entries and prepared to do an
advanced uninstall/removal. This searches for leftovers the native uninstaller conveniently misses.
4. I initiated "Windows installer clean up" on all SQL entries at about the same time as I initiated an advanced uninstall with revo, so one wouldn't plausibly gut whatever the other one needs to do its job before its too late; ok kind of nutty, but you can combine this in various ways until it works for you, if it doesn't the first time like it did for me.
5. Windows installer clean up won the race and left behind much if not all of the files on the hard drive, but probably worked most of its magic in the registry.
6. Revo-Uninstaller completed and cleaned up whatever junk was left on the hard-drive, there were next to no registry entries reported left behind.
7. I tried installing sql-sever again, this time with "Install Program
With Revo-Uninstaller", think of this as "Process Monitor" for installations. This time SQL installed without a hitch for the first time in a year after dozens and dozens of previous attempts. PLUS Revo has detected over 12,125 registry
keys and logged everything necessary to clean it up absolutely 100%; user rights and all...
You can copy and repeat with whatever versions you believe you have installed previously to ensure you get every last bit of junk out of there. This basically overrides what was already on there before but gives you a convenient log that automates the process
of removal for a later time so you don't have to. I recommend, then, using SQL's built in uninstaller, to remove itself PROPERLY this time, THEN run the Revo-Uninstaller's LOG based removal system AFTER.... this way you're good to go.
I hope this saves you a whole lot of troubles!