SemiCharmed

I recently bought GTA: San Andreas for PC and began installing it when a windows explorer error occurred around halfway through installation causing windows to restart. Now when I insert the game it gives me the option to 'Play' which when clicked brings up a quick Demo Shield icon and then nothing (since it's obviously not fully isntalled). When I try to 'Uninstall' I receive the following error message:

Setup has experienced an error.

Please do the following:
-Close and running programs
-Empty your temporary folder
-Check your internet connection [Internet-based setups]

Then try to run setup again.
Error Code: -6003


Well obviously I did everything it told me to do, I also have Vice City downloaded on my PC, but it appears that GTA San Andreas doesn't show up under Program Files, only under the Start menu. I was instructed on another tech forum to download Ccleaner and clean out my registry and all that to try and get all the extra files deleted so I could do a clean install. So I deleted the GTA: San Andreas link under the start menu, then I ran Ccleaner, deleted/fixed everything it found and i'm still getting the same problem with the same error message. I've deleted my Temp folder and all that good stuff too. Any help or ideas would be GREATLY appreciated. Here are my system specs:

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System Information
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Time of this report: 4/22/2008, 17:45:26
Machine name: FLASHCAD
Operating System: Windows XP Home Edition (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_gdr.070227-2254)
Language: English (Regional Setting: English)
System Manufacturer: Compaq Presario 05
System Model: DA203A-ABA 6330US NA850
BIOS: Award Modular BIOS v6.0
Processor: Intel(R) Pentium(R) 4 CPU 2.00GHz
Memory: 510MB RAM
Page File: 372MB used, 873MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.2180 32bit Unicode

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Display Devices
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Card name: NVIDIA GeForce4 MX 420
Manufacturer: NVIDIA
Chip type: GeForce4 MX 420
DAC type: Integrated RAMDAC
Device Key: Enum\PCI\VEN_10DE&DEV_0172&SUBSYS_00000000&REV_A3
Display Memory: 64.0 MB
Current Mode: 1024 x 768 (32 bit) (60Hz)
Monitor: Plug and Play Monitor
Monitor Max Res: 1600,1200
Driver Name: nv4_disp.dll
Driver Version: 6.14.0010.9371 (English)
DDI Version: 9 (or higher)
Driver Attributes: Final Retail
Driver Date/Size: 10/22/2006 12:22:00, 4527488 bytes
WHQL Logo'd: Yes
WHQL Date Stamp: n/a
VDD: n/a
Mini VDD: nv4_mini.sys
Mini VDD Date: 10/22/2006 12:22:00, 3994624 bytes
Device Identifier: {D7B71E3E-4232-11CF-2B47-0A2002C2CB35}
Vendor ID: 0x10DE
Device ID: 0x0172
SubSys ID: 0x00000000
Revision ID: 0x00A3
Revision ID: 0x00A3