First, it may be nice to know where Windows is getting the
C:\Users\sobhan\Desktop\Adobe Acrobat XI\Adobe Acrobat XI\AcroPro.msi
from. I suspect you'll be able to see that command if you go to a command prompt and run this:
reg query HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall /s | find /i "UninstallString" | find /i "Adobe Acrobat XI"<BR>
It doesn't seem like you need to have a UAC-elevated command prompt. (However, some programs do give different results based on if UAC is enabled. Most give an error message, like "
net session", but others just give a different result.)
You can chop off everything after the pipes if you want to see more info, like the DisplayName value.
Note: If you choose to use the graphical interface, RegEdit, then you should know that HKLM is a shortcut for HKEY_LOCAL_MACHINE
I'm noticing the
Adobe Acrobat XI\Adobe Acrobat XI\AcroPro.msi filename you mention is under your Desktop. My guess is that these files got deleted, likely in an attempt to clean up a desktop. You could try to somehow restore the file to that location, but that probably won't be super easy and so it won't be worth the effort. In all honesty, you're probably more likely to be better off just using a method to manually clean off the software (deleting the files), and then eliminate the related entry from HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall
Just deleting the files (for the old version) may not seem like a very thorough cleaning job, as that approach may leave behind some registry entries. However, chances are that nearly every one of those remaining registry entries are likely to just be used once you get the new version installed, so you can rest easy knowing that you're not leaving a ton of useless clutter in the registry.
Now, as for why you can't install, I don't know. I don't think people should be expected to know, based on the very limited information you've provided so far. There are probably tons of different reasons that an installation program could break. I remember working for a computer support company and a business just couldn't get their Adobe installed. Turns out that an employee had run some software that cracked the old version of Adobe, and that software modified the HOSTS file (in C:\Windows\System32\Drivers\etc) which had a bunch of lines related to Adobe. (And we had a very good idea of just what employee did such a thing.) I cleared out those entries from the HOSTS file, and may have done some more work (like flushing the DNS cache, with IPConfig/FlushDNS), and then I was easily able to register the new version (like what the business was trying to properly do). So that's a real-world experience that did happen.
However, I do suspect your cause may be entirely different. Because there are numerous reasons why a software installation could fail, finding out why Adobe won't install is probably really worth a separate question by itself, and more details on what you experience when you try to install it.