Greedy patching: Hot patching is a way to quickly install security updates without requiring an OS reboot. Microsoft has offered the feature for years through its Azure cloud platform, but it's soon coming to non-cloud versions of Windows Server. It won't be free, but Microsoft's target audience is enterprise customers. Microsoft says hot patching works by modifying the code of active processes in memory, avoiding the need to restart them. The service, which entered preview in 2024, will become generally available for Windows Server 2025 starting July 1. However, it will require a monthly subscription, priced at $1.50 per CPU core. Hot patching has been available for years in the Windows Server Datacenter edition. Microsoft says the Xbox team used it to shrink maintenance windows from weeks to days. While the feature enables smaller, faster update packages, customers will still need to reboot systems four times a year to apply full "baseline" operating system updates. Organizations and individuals can begin testing hot patching for Windows Server today through Azure Arc. Microsoft will convert the service into a paid subscription on June 30, so users must manually opt out before then to avoid automatic billing. Hot patching is not the only way to keep Windows systems current without rebooting. Microsoft notes that some changes – such as non-security fixes, .NET framework improvements, and updates to drivers or firmware – can now be applied without requiring a restart. These scenarios help reduce downtime even without a paid hot patching plan. In-memory patching is not a new concept, nor is Microsoft the only one using it. For instance, the 0patch initiative has offered 'micropatching' services for years, allowing users on older Windows versions to remain protected against modern internet threats, even beyond official support. // Related Stories Security firm Acros notes that 0patch is significantly more affordable than Microsoft's post-support patching services. However, an official first-party hot-patching solution from Microsoft will likely offer better management options, making it a more practical choice for businesses deeply integrated into the Microsoft ecosystem.