> Is it plausible to do a clean install of W2K and E2K on a new > harddrive the databases are small) and copy over exchange 5.5 > information stores? Well, that depends on what you mean. If you are suggesting that you are going to copy your databases and then do an in-place upgrade of the databases on a second box then sure. The issue is that the copied databases are going to become stale and you'll have new messages on the other server. This is a much bigger upgrade than you might realize. My company might be larger than yours (2 dozen servers and 3 Exchange servers) but I spent about 6 months going from NT4/Exch5.5 to Win2k/Exch2k. How many servers do you have? PDC/BDC's? If it is just one box then maybe I would do it entirely offline using a 2nd server and then just swap them. Another approach is to build a an Exchange box and just move the mailboxes to the new box one at a time. In any case, I think you should consider the Win2k upgrade and the Exch2k upgrade as TWO projects. Doing both at once is too much, imho.