Rebooting a machine to apply the latest patches can mean significant downtime for a server, which is why Windows supports a run-time method of patching, called a hot patch (or simply hotpatch), in contrast to a cold patch, which requires a reboot. Hotpatching doesn’t simply allow files to be overwritten during execution; instead, it includes a complex series of operations that can be requested (and combined). These operations are listed in Table 3-28.
Table 3-28. Hotpatch Operations
Replacing a DLL that is on the disk and currently used by other applications, or replacing a driver that is on the disk and is currently loaded by the kernel
When an entire library in user mode needs to be replaced, the ...