Cannot install System Update 4 on Thinkpad W520 running Win7 Prof 64

Question

I am having problems installing system update 4. I originally installed it and had the problem with running it and getting the tvsu error message that is addressed in another thread.
I uninstalled it then ran two registry optimizers and reinstalled .Net and now I can't even install it. When I do I get the following:
This setup will perform an upgrade of '!@^'. Do you want to continue? Yes or No.
I click Yes and it runs some more until this pops up:
Error 2753. The File 'startsuservice.exe' is not marked for installation.
Click OK then the installation program finishes but does not complete. I even tried to uninstall and reinstall the entire toolbox and that does not work.
I have a W520 running Win7 64.

Answer 1

Thanks for the thoughtful response. See my answers in bold.
sclexman wrote:
You opened this thread in June 2012, and Now you are back to give us an update.
Slicing and dicing the registry is NOT the solution.  Why not, if you know what you are doing? Guess the MSI installer is not the answer. I would NEVER use a registry cleaner, EVer.  It over cleans. No argument there.
(1) Does programs and features show System update installed? No IF so try to uninstall.
(2) Install System Update 5.0.2 and post the results.  Won't install. If it did, what results would I post? Install on top of version 4 and see what happens. SU is not installed. Support of your laptop does NOT show version 4 available for download.
(3)This  system was factory shipped win 7 (released feb 22,2011)  did system update ever work out of the box? No.
(4) What version of . Net installed? v4 3.5 SP 1 is needed. NO need to uninstall/reinstall. You are overworking yourself. Agreed
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You state you used 2 registry cleaners, and from feb 2011  until your June 2012 post, was all well with your system? Yes, a couple of other problems were actually fixed but not this one. Based on all of the experts disdain for these cleaners, I guess I was lucky that they didn't cause more problems.
I would backup your user data and factory install.  No, too much work. See foot, it has a hole in it. ?????
When did you receive this laptop, like before June 2012? purchase date? June, 2011
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Your original post:  
 I originally installed it and had the problem with running it and getting the tvsu error message that is addressed in another thread. 
When did you run registry cleaners?  Approx. between 6/11 and 6/12. After the tvsu error message that is addressed in another thread?  Yes
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Your most recent post referred to a workaround. This involves SU version 5. It wont reinstall, seems SU service (old) pointing to non existent folder.  New SU just released. You are version 4.  So? Any version I try to install fails with the same message.
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I do problem determination on main frames. Been doing it for 30 years.  I did the same early in my career. Gather the facts.  In your case, original, ,  System update msg error. Did something else occur(registry cleaner). Some times the interview points to the most simple solution. Oh, really? The easy fix would be to bypass the point in the install process that is pointing to a previous version that does not exist or find the offending registry entry that is deceiving the install process and delete it.  But I can't do that because I am not a MS/PC software engineer and I can't seem to find one who can help. OH, change parm=0 to parm =1 or install the newer version. Where? Simple. You over killing it.
What I like to call tourist Information...(couch potato), .. so. bottom line,  in June 2012, version 4 SU gave me a error message. That is where we start. That would be nice but no one has ever solved the original problem in this forum.