Windows Vista update error code 646 and associated update installation problem

Do you have UAC (User Account Control) enabled?

Why it would just suddenly start affecting Windows Updates now, I can't say... but it *could* cause this type of problem, so it would be worth disabling it, until after the updates have installed successfully?

If you don't use UAC, I'm at a loss, unfortunately :emotion-6:

Do you have UAC (User Account Control) enabled? Why it would just suddenly start affecting Windows Updates now, I can't say... but it *could* cause this type of problem, so it would be worth disabling it, until after the updates have installed successfully?   If you don't use UAC, I'm at a loss, unfortunately :emotion-6:

Real Fireblade-

Thanks much for your very useful advice.  I haven't touched my UAC controls since I got the PC, and when I accessed it, I could not tell if it was activated or not.  Nonetheless, I unchecked the activate box to deactivate it and tried installing the updates again.  This time the updates installed successfully and quickly and I didn't have to turn off my PC's two firewalls.  Although I am happy deactivating the UAC allowed the updates to install properly, I am curious why the UAC would affect update installation.  Can I ask how you considered the UAC to affect the update installation?  In any case, thanks so much again for your fast and successful advice!

PG

I had the EXACT same problem!  Kept getting the 646 error code just recently and it wouldn't install my 37 misc. updates.  The only thing I had changed recently was install Microsoft Office Student Edition.  So strange that it was the exact same situation as the above mentioned!  Anyhow I just tried unchecking my UAC controls as Real Fireblade had mentioned and it worked for me too!  I am sooo... excited!  I too am curious as to why that would affect the installation.   Hmm.. quite strange.  Anyhow, thanks so much to both of you.  I am pretty unknowledgable of computers and was so happy to find a quick and reliable solution to my problem :)

SJ

I had the EXACT same problem!  Kept getting the 646 error code just recently and it wouldn't install my 37 misc. updates.  The only thing I had changed recently was install Microsoft Office Student Edition.  So strange that it was the exact same situation as the above mentioned!  Anyhow I just tried unchecking my UAC controls as Real Fireblade had mentioned and it worked for me too!  I am sooo... excited!  I too am curious as to why that would affect the installation.   Hmm.. quite strange.  Anyhow, thanks so much to both of you.  I am pretty unknowledgable of computers and was so happy to find a quick and reliable solution to my problem :) SJ

Thanks for sharing your experience.  I'm sorry you experienced the same frustration as I, but happy to know you were able to solve it the same way.  I still don't know why unactivating the UAC control would make such a significant difference...but I am happy nonetheless the solution seemed to work so well.

PG

I have the exact same issue.

After Nov 11th, most updates do not install successfully.  I have a Dell laptop that I'm using.

What works for me is to go to the Microsoft website and download each update manually from there.

I'm wondering why this has suddenly happened since Nov 11th?

I've had the same issues...starting in November...all with MS Office updates. It's wierd. I didn't install anything..updates for these just started to not be installed properly. Contacted MS and they said it was  update components being corrupted. Running their Fix It tool with disabling UAC has helped the past 2 months.

Thanks for the tip.  I too was having the same error issue.  Once I disengaged my UAC I was able to update my windows.

On a side note.  I did not install any other programs in November like some of the other posters had.  My issue just started in November.  End of story.

Hi! I posted earlier if you read up above...  Just wanted to let you know that when I disabled the UAC and installed the updates everything was great!  I immediately went back in after the update was complete and enabled the UAC again.  Since then I have had no further problems with any other updates.  Apparently it was only the one major update back in Nov/Dec. that was affecting all of the other updates to not go through.  I think you'd be safe reactivating your UAC and hopefully you won't have any further problems... if you do just go back in and go throught the process all over!   Good luck!

S.Jast

So you think it's just the UAC that needs to be turned off and maybe not even bother with the Fix It tool? I wonder...guess I'll try just turning th UAC off and trying to install them next time updates come around. Btw, were the updates for MS Office at all? Those are the only ones I have issues with since November.

Hi, thanks for all your help! I will for sure try disabling the UAC before trying the updates. I, too, did not install any new programs when all this started in November. Hope things continue to go well for ya! So glad it worked for you! =) Happy updating!

Absolutely.  I was having trouble since November trying to install the MS Office (word, excel etc).  I even went on line to find solutions.  Everyone wanted you to buy their product.  Then today I came across this feed.  They talked about turning the UAC off and so I did that.  Sure enough I opened up the windows update screen on the start menu and downloaded the 4 updates and it worked this time.  Of course, now my computer is squaking I need to turn the UAC back on.

Thank you, I will turn back on my UAC.  Happy posting.