i am trying to update my computer but everytime i try the thing turns red and gives m the error code 646i would love some help on how to fix it or just how to update my computer

There is a specific forum for Windows Update issues - http://social.answers.microsoft.com/Forums/en-US/vistawu/threads. You should probably respost your question there. When you do so, please make sure to indicate what operating system you're talking about.Paul Adare CTO IdentIT Inc. ILM MVP

Hi, What system are you running? Please let me know the exact wording of the error code or error message. Tim Quan - MSFT

please let us know what u see under HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU

hi i tired to do the windows update and a error comes up as code 646 i cant get it fixed can u help me please

code 646

Hi I had the same problem and i found the exact step to follow here you go For Windows 7 and Windows Vista users Click Start, and then in the Start Search box, type regedit. In the Programs list, right-click Regedit.exe, and then click Run as administrator. If you are prompted for an administrator password or for confirmation, type the password, or click Continue. Locate and then click the following registry subkey: HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders In the details pane of Registry Editor, locate AppData. The value of this key should be %USERPROFILE%\AppData\Roaming. If the value is not set to %USERPROFILE%\AppData\Roaming, right-click AppData in the details pane, and then click Modify. Enter %USERPROFILE%\AppData\Roaming into the Value data box, and then click OK. Close Registry Editor. Try to install the update again. If the problem persists, repeat these steps but use the following registry subkeys instead of the subkey that is specified in step 3: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

This fixed it for me http://www.microsoft.com/downloads/en/details.aspx?familyid=807426a1-8b78-4681-a606-dc39f4d7b64a&displaylang=en

Wanted to say thank you...worked for me!!!

Thanks, this worked for me

thanks Big Mike, i think this was the easiest fix I have done how you figured this one out, I ll never know mike

Regedit did the trick for me too.

I had the same problem and did something so simple I was sure it wouldn't work. Get this: I turned off my router (so went totally offline) and then installed my 10 updates that were coming up with the 646 error code. What happened? SUCCESS! I turned my router back on and my computer works without any more issues (as far as said updates are concerned). I hope this will be helpful (and much easier) for those who are getting that pesky 646 error.

Thanks for this info. I was battling with trying to find the right registry string to solve the issue. Thanks a bunch.

That was only a coinicidence Tomek69. The issue is caused by a corrupt registry string value. Your issue remains. However you should follow Big Mikes post on how to navigate to correct it or in your case...check to make sure that the registry string is correct or future mystery issues may insue. Good Luck

Thank You!!!!! I've been trying to get these updates to install since August!

Bigmike282, WOW.....Thanks. Worked like a clock at step 6 (after giving up). Really good job.

This worked for me PERFECTLY!!! THANKS

This worked for me PERFECTLY!!! THANKS thanxz big mike...... worked for me tooo ... ! excellent stuff from ya !!

thanxz mike ... it was done in a flash !

thankz alot...its really workout....

Regedit worked like a charm!

Big Mike, Thanks for the info. Although I dont like to mess in the registry, your information corrected the error. I appreciate your time and efford in helping. Merry Christmas.

good advice it worked for me

Thanks bigmike282. It amazes me how people know this stuff. I'm glad I found this forum. Worked perfectly!! THANKS!!

just wanted to tell you thanks! it worked for my computer! :D

Thanks you bigmike. it worked for my windows 7 64bit pc.

Thanks you bigmike. it worked for my windows 7(64bit) pc.

Thanks so much... This was a big help.... I've been dealing with this issue since August 2009! Dell techs would help but obviously they only did a temp fix.

THANKS bigmike282!!!! Worked like a charm!

thank you bigmike282!!!!!!!!!!!! YOU ARE THE MAN or Women as in the net only you know your sex lol A big thanks to you very good inst. THANKS AGAIN

Hi, Thank you. It worked perfect:)

It did work, and the updates were installed, Thanks

TY! This worked perfectly.

Thanks Dude

The solution here http://support.microsoft.com/kb/2258121 you can download Fix it for me at http://go.microsoft.com/?linkid=9737449 or choose Let me fix it myself as bigmike282 said above

This link here helped me: http://cyberst0rm.blogspot.com/2011/05/how-to-fix-error-646-when-installing.html Hope it helps others too.

Hi, “Error 646″ can occur if there is any issue with Windows Installer. This error can also occur due to the corrupted registry of Windows 7. As registry is the place where all the details of the software and other files in your system are stored, any issue in the registry due to wrong keys can be a reason for the error. Registry corruption is due to the installation of malware and other viruses in your system. Get more information to fix error code 646 : http://supportformicrosoft.iyogi.com/windows-7/windows-7-error-646.html Hope this helps you.