MSExchange MTA Errors

I upgraded my server from NT 4.0 to win 2k and now attempting to upgrade my Exchange from 5.5 to win 2k. Now I am recieving the following errors.
ID 9406 There is not enough performance Monitor memory to display the MTA connections information.
Category: Resource
ID 137 A fatal directory error occured.
Category: Directory access
ID 9405 An unexpected error has occured which may cause the MTA to terminate. Error: Init Routing API returned error – 1073478767.[Base Main Base 1](16)
Category: Field Enginering

The server has 512 of memory and the Paging file is on drive D: and is 1000 min.

I tryed the microsft site on the error and the ones I found were vage.