How did you setup linked server, Using Microsoft OLE DB Provider for ODBC or Microsoft Jet OLE DB Provider?

Backup and restore.

Could it be the database in second instance do not need more memory to run? You could switch the SQL Server instance1 to node2 to test that.

Did you install the EM during the installation? Check whether "SQL Server Enterprise Manager.MSC" file is in location "\Program Files\Microsoft SQL Server\80\Tools\Binn".

Which version of SQL Server do you use, MSDE?

Try to modify the registry to change it back and see what is going to happen and post back.

http://support.microsoft.com/default.aspx?scid=kb;en-us;325003&Product=sql2k

Try to restore the database backup file into local drive and then restore the database using SQL Server statement "retsore" to restore the database.

No quite understand your question. SQL Server will rollback the failed insert transaction automatically if the insert fails. You may provide some samples here.

You should run DBCC CHECKDB without repair option to ensure the database is in intergrity prior to back it up. That will ensure you have good database backup.

How large is...

SQL Server maintains statistics for queries that use temporary tables but not for queries that use table variables. Without statistics, SQL Server might choose a poor processing plan for a...

Use openrowset to access remote data from an OLE DB data source. It is an alternative to accessing remote data in other servers using OLE DB.

declare @date1 datetime

declare @date2 datetime

select @date1 = '2004-05-11 00:00:00'

select @date2 = '2004-05-09 11:45:00'

select cast((cast(datediff(mi, @date2, @date1) as int) / 60) as varchar(5)) + ':' +

...

You have either conatct microsoft or restore from your database backup.

Are you able to access those databases?