How to increase the Exchange SP2 storage limit to 75 GB

I had a question last night on how to increase the Exchange Storage limit for Exchange 2003 SP2. The You Had Me at EHLO blog has the details. The short form is:

1. Figure out how big you can make your store on your server based on hard drive size


2. Browse to HKLM\ SYSTEM\ CurrentControlSet\ Services\ MSExchangeIS\ {SERVER NAME}\ Private-013e2e46-2cd7-4a8e-bfec-0e4652b94b00
   
3. Create a REG_DWORD called "Database Size Limit in GB" and enter the DECIMAL value (ie switch the input to DECIMAL) in GB you want to use from 1-75

Restart the Exchange Store service

You should read the actual blog posting by the Exchange team, it's much more complete and provides more configurable options.

Then what I did, was divide the amount you alloted for the whole store, by 75 max users to find your new quota/user. If you're never going to go that high, then do the math differently, just don't forget the quotas when you're adding new users.

From experience, a corupted Exchange store is not fun, especially when it happens on Thanks Giving Day at 5pm.