Over the weekend SonicWall, makers of internet security appliances, inexplicably started blocking WindowsUpdate. Also blocked are updates from Kaspersky and Trend Micro antivirus products. Linux users around the world may be rejoicing, but system administrators using SonicWall appliances might feel differently. Thankfully you can disable this set of checks easily enough, so the long-term effect will be minimal.

Why have these checks at all? So that corporations can block individual machines from directly accessing these update services, since many companies will be using  Windows Server Update Services to spool out updates from a local server in order to minimize bandwidth consumption, and to ensure that updates are applied according to local policy instead of Microsoft’s Patch Tuesday. Still, it could be jarring for sites not using WSUS to suddenly find all access to Windows Update blocked!