I use Windows XP Professional with SP3 and for more than 2 weeks I have been trying to install windows security update KB2564958 and i will fail to install giving error code 0x80246007. I looked up this error code online and it means “NOT DOWNLOADED” but I am sure it was downloaded because I went directly to microsoft.com and looked up the stand alone of this update and downloaded it and my download manager showed the progress bar downloading 744 KB which I saved to desktop but when I tried to onstall it the setup was interrupted at the beginning saying “Setup was cancelled”. I have scanned my pc with Spybot, Malwarebytes, Superantispyware, Norton Security suite and they found no viruses or troyans at all (note that I don’t have any antispyware actively monitoring on task-bar I use all of them manually to scan so there is no conflicts). I ran Chkdsk and found no errors. I ran Registry First Aid and clea-ned the registry to no avail, this up-date will not install. There must be some bug or this update was corrupted since they offered it. I have tried several options that I found online and did not solve the issue. My Norton protection and all other softwares never interfered with Microsoft Updates. I contacted Microsoft support and after they gave me a list of several options to solve the problem that I followed to the letter to no avail they asked me to use (and pay) phone support and I replied to them that Microsoft offers FREE complete support for problems related to Windows security updates and I refuse to pay for that support. That was a week ago and they have not responded at all they left me on my own. I don’t know if some of you have had problems trying to install this update but if you found a solution please share it with us.