Hi fellows! Recently i've found in my computer there were some updates errors checking Windows Update history. The issue is always associated to SECURITY & QUALITY ROLLUP for .NET Framework updates & it started around Nov. 2018 when KB4457918 failed -643 code error-. There was the same 643 error in a row with updates KB4467240 (Nov 2018), KB4481480 (Jan 2019), KB4487256 (Mar 2019), KB4487078 (Mar, Apr, May 2019) & finally KB4499406 -also May-. I´ve tried all Microsoft "helping hand" procedures included in Windows Update page to solve that problem without any success. It is important to note that all the rest of updates (Security Monthly Quality Rollups, Malicious software Removal tools & Win 7 updates) were installed correctly without any trouble. So, even though my computer is running ok till today, Im áffraid & very worried about it, knowing there is a risky security failure in my system. OS running is Windows 7 Ultimate Service Pack 1 & I followed your instructions to post my thread, so i`m dropping here the CBS folder link -Google Drive- CBS.rar\nHoping data from my pc´s stuff -here included- could serve to help to work out that issue (help I humbly ask) & waiting for news from U...\nRegards & thanks in advance.