Update on the scenario of my inquiry:

We are able to try using a Dual Core PC with 4GB Memory (Windows 2008 Enterprise, SQLServer 2008 Entreprise).

Guess what? Number of users increases...

Good day sir, i just provide the necessary settings and configuration but the improvement is around 1 to 2 secs:

About the index creation, i cant create unique nonclustered index due...

Got it Sir!

I'll be in the client's area to test all plans and configuration...

I'll post the result afterwards....

Thank you very very much sir!

@michael-2, sir you're right... i didn't able to put indexes in DRSummTemp table (this is just an extension table handling current records). The original table contains nulls...

@gilamonster

CREATE TABLE [dbo].[DRTemp](

[ID] [bigint] IDENTITY(1,1) NOT NULL,

[DRNo] [nvarchar](15) NOT NULL,

[DRDate] [datetime] NOT NULL,

[CustNo] [int] NOT NULL,

[TotalAmt] [money] NULL,

[TotalQty] [int] NULL,

CONSTRAINT [PK_DRTemp] PRIMARY KEY CLUSTERED

(

[ID] ASC

)WITH (PAD_INDEX...

Thank you tom.lemmer, GilaMonster, Michael Vessey for the response...

Correction on the specs i provided last time (just receive the full info from the client)

*Quad-Core Xeon E5420 (2x6 MB cache) 2.50...