Try running it uder account having sysadmin privilege. Read about Execute As at http://msdn.microsoft.com/en-us/library/ms188354(SQL.90).aspx.

MJ

No different steps for SQL 2008.

MJ

I don't see any harm in running on system databases.

MJ

Check:-

How to Set the /3GB Startup Switch in Windows

http://technet.microsoft.com/en-us/library/bb124810.aspx

MJ

Please post the error message.

MJ

Have you tried running it on active node?

MJ

Do you get any rows in output when you run the below mentioned query:

select * from sys.databases

where compatibility_level<>100

MJ

Are you running it against sql 2000/2005 server instances?

MJ

Do you have any login related information in your central database table so tht script can take the login information from there to add each server as a link server...

Check this-->http://www.quest.com/Quest_Product_Demos/LiteSpeedforSQLServer_demo_043007/chap02.htm

MJ

Is your sql instance MSSQLServerADhelper service running under local account or domain account? Try an domain account with admin priveleges.

MJ

Check for index fragmentation and also don't forget to leave enough memory for OS.

MJ

Try this:

Drop the existing database and then do your restoration

Or

Would be good if you post your restore statement here.

MJ

To view buffer pool size you are going on the right track

The DMV sys.dm_os_sys_info can be used to view the amount of buffer memory, bpool_commit_target show "target" memory limit for...

Do you see integration services and workstation components under "SQL Server 2005 Common Components" category when you click on MIcrosoft SQL Server 2005-->Change-->.... under Add or Remove Programs in Control...