A. A. This could well be a known issue with SNMP caused when SNMP managers that come with some server management tools (especially with HP servers) register a lot of SNMP extensions. Specifically when the registry entry at HKLM\System\CCS\Services\SNMP\Paramaters\ExtensionAgents got to around 1K or more. This problem only affects SQL 6.x - SQL 7.0 and above are unaffected.
You can either remove the SNMP service before installing SQL Server (and re-install afterwards), or try the following workaround.
1. Stop snmp service
2. Save the contents (all the values) of the mentioned subkey (use regedt32 for these operations)
3. Delete all values except the one with the 'largest' name (the names are composed of digits)
4. Install SQL Server
5. Check the 'extensionagents' subkey. Setup will have added a value entry for SQL Server. Save the key name and value somewhere so you can manually add it again later.
6. Restore all 'extensionagents' values previously saved in step 2
7. Add the sqlserver entry as it will have been deleted in the previous step
8. Re-start snmp
If you re-install snmp then remember to re-apply your NT service pack to keep all the system dll's in synch.