Depends on when you installed your licenses.
If your TS CALs were installed *after* SP3 (which included a
Licensing Enhancement) was applied to the Terminal Server and
the License Server, then they have an expiration date of 52-89
days. Licenses that are not used (because the client does not
connect to the TS anymore) will automatically be returned to the
LS after the expiration date. In the meantime, your new clients
will get a temporary TS CAL, which is valid for 90 days.
Note that these time periods are choosen to make sure that your
temporary license lasts long enough for the old license to become
available again. So if your TS CALs have an expiration date, and
you are reaching the end of the 90 day temporary license period
without having TS CALs available, it means that you have too few
licenses and you simply have to buy extra TS CALs.
If you installed your TS CALs *before* SP3, then they will not
have an expiration date and be permanently issued to the clients.
These licenses will be lost by a fresh re-installation of the
client OS, or if the client is discarded altogether. You will have
to phone the Clearinghouse to get these TS CALs re-issued.
For detailed information, check the "License Transfer and Token
Recovery" section of the
Windows 2000 Terminal Services Licensing FAQ
http://www.microsoft.com/windows2000/server/howtobuy/pricing/tsfaq.
asp
291795 - HOW TO: Locate a Phone Number for the Microsoft
Clearinghouse
http://support.microsoft.com/?kbid=291795