KMS Activation Renewal
180-day renewal cycle, activation count window, and configurable intervals
A client activated through KMS is licensed for a fixed period — by default, 180 days— and must contact a KMS host within that window to renew. If renewal does not occur before the deadline, the client returns to a Notification state until activation succeeds again. The 180-day period is the activation validity interval and is not directly configurable.
Activated clients attempt to renew every 7 days by default; unactivated clients retry every 2 hours. Both intervals are configurable on the KMS host with slmgr.vbs /sri and slmgr.vbs /sai respectively, in minutes.
See also: Key Management Service, KMS Host Configuration, slmgr Command Reference.
History
The 180-day activation validity interval and the activation count window were introduced with Volume Activation 2.0 in Windows Vista and have remained stable across every subsequent Windows and Office release. The defaults reflect a deliberate design choice: a fleet that loses access to its KMS host has approximately six months to restore service before clients begin to drop out of activation.
Technical details
Renewal traffic is identical to initial activation traffic — an Activation 2.0 RPC over TCP 1688 with a CMID — so a successful renewal also keeps the host's rolling CMID cache populated. The host maintains a CMID cache equal to twice the activation threshold (50 entries for client SKUs, 10 for server and Office); a CMID that has not been refreshed within the cache eventually ages out and ceases to contribute to the count.
Intervals
| Parameter | Default | Configured with |
|---|---|---|
| Activation validity (client licence life) | 180 days | Fixed (per product) |
| Renewal interval (activated client) | 7 days (10,080 minutes) | slmgr.vbs /sri <minutes> |
| Activation retry interval (unactivated client) | 2 hours (120 minutes) | slmgr.vbs /sai <minutes> |
| KMS host CMID cache size | 2× activation threshold | Not directly configurable |
| Client activation thresholds | 25 (client) / 5 (server, Office) | Fixed |
| Out-of-Box grace period | 30 days from install | Fixed |
Registry values
Renewal-related state is stored under HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SoftwareProtectionPlatform. Notable values include KeyManagementServiceName (configured KMS host), KeyManagementServicePort, VLActivationInterval (activation retry interval in minutes), VLRenewalInterval (renewal interval), and DiscoveredKeyManagementServiceMachineName (last KMS host discovered via DNS). The values are intended to be configured through slmgr.vbs; direct registry editing is not supported.
Common issues
- Client never renews. Renewal is attempted by
sppsvcin the background; if the service is stopped the timer does not advance. Verify thatsppsvcis running. - 180-day clock not extended after manual /ato. Each successful activation resets the clock; verify with
slmgr.vbs /xpr, which prints the new expiration date. - Host count drops after image refresh. Reimaging without
sysprep /generalizereuses the CMID, so newly imaged machines do not contribute fresh CMIDs to the count. - Custom renewal interval ignored. Custom values set with
/srirequire a restart ofsppsvcon the affected host to take effect.
References
- Activate using Key Management Service — https://learn.microsoft.com/en-us/windows-server/get-started/activation-key-management-services
- Slmgr.vbs options for volume activation — https://learn.microsoft.com/en-us/windows-server/get-started/activation-slmgr-vbs-options
- Plan for volume activation — https://learn.microsoft.com/en-us/windows/deployment/volume-activation/plan-for-volume-activation-client
- [MS-KMS]: Key Management Service Protocol — https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-kms/1ab09b40-e30c-457c-bd2a-23e1287c1bd5