WPF Application slowing down on i5 Processor machine

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WPF

performance

One of the developed application in WPF is running very slow on i5 process Laptop.
UI contains multiple user controls (200+) in nested Items control. Same application is running with good performance in one of the Desktop machine.

Below is the detailed configuration of Laptop where its very slow (50 sec to render the UI) :

Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_gdr.101209-1647)
System Manufacturer: LENOVO
       System Model: 2537W2K
               BIOS: Ver 1.00PARTTBLx
          Processor: Intel(R) Core(TM) i5 CPU       M 520  @ 2.40GHz (4 CPUs)
             Memory: 3060MB RAM
          Page File: 784MB used, 5172MB available
        Windows Dir: C:\WINDOWS
    DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
     DxDiag Version: 5.03.2600.5512 32bit Unicode

Display

Card name: NVIDIA NVS 3100M
     Manufacturer: NVIDIA
        Chip type: NVS 3100M
         DAC type: Integrated RAMDAC
       Device Key: Enum\PCI\VEN_10DE&DEV_0A6C&SUBSYS_214217AA&REV_A2
   Display Memory: 256.0 MB
     Current Mode: 1680 x 1050 (32 bit) (60Hz)
          Monitor: ThinkPad Display 1440x900
  Monitor Max Res: 1440,900

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Below is the detailed configuration of Desktop where its fast (6 sec to render the same UI) :

Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_gdr.101209-1647)
System Manufacturer: Dell Inc.
       System Model: OptiPlex 755                 
               BIOS: Phoenix ROM BIOS PLUS Version 1.10 A04
          Processor: Intel(R) Core(TM)2 Duo CPU     E6550  @ 2.33GHz (2 CPUs)
             Memory: 2004MB RAM
          Page File: 1544MB used, 2353MB available
        Windows Dir: C:\WINDOWS
    DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
     DxDiag Version: 5.03.2600.5512 32bit Unicode

Dispaly Card

Card name: Intel(R) Q35 Express Chipset Family
     Manufacturer: Intel Corporation
        Chip type: Intel(R) GMA 3100
         DAC type: Internal
       Device Key: Enum\PCI\VEN_8086&DEV_29B2&SUBSYS_02111028&REV_02
   Display Memory: 384.0 MB
     Current Mode: 1280 x 960 (32 bit) (60Hz)
          Monitor: Plug and Play Monitor
  Monitor Max Res: 1600,1200
      Driver Name: igxprd32.dll
   Driver Version: 6.14.0010.4837 (English)

Please help me to understand the cause to slow down the rendering.