Monitor blacks out after running for about 25 mins

Please include the model number of your computer or motherboard. Audio is not included in processor.

If you mean AutoCAD then you need the following:


You can get more information at:


http://usa.autodesk.com/autocad/system-requirements/

For 32-Bit AutoCAD 2012

• Microsoft® Windows® 7 Enterprise, Ultimate, Professional, or Home Premium (compare Windows 7 versions); Microsoft® Windows Vista® Enterprise, Business, Ultimate, or Home Premium (SP2 or later) (compare Windows Vista versions); or Microsoft® Windows® XP Professional or Home edition (SP3 or later)
• For Windows Vista or Windows 7: Intel® Pentium® 4 or AMD Athlon® dual-core processor, 3.0 GHz or higher with SSE2 technology; for Windows XP: Intel Pentium 4 or AMD Athlon dual-core processor, 1.6 GHz or higher with SSE2 technology
• 2 GB RAM
• 2 GB free disk space for installation
• 1,024 x 768 display resolution with true color
• Microsoft® Internet Explorer® 7.0 or later
• Install from download or DVD

Most probably your hardware ie graphic card do not support software requirements.

Autocad 2009 system requirements for Win XP.
32-bit AutoCAD 2009
Running under Windows XP:
•Microsoft Windows XP SP2 operating system
•Intel® Pentium® 4 processor or AMD Athlon®, 2.2 GHz or greater
or
Intel or AMD Dual Core processor, 1.6 GHz or greater
•1 GB RAM
•750 MB free hard disk space for installation
•1024x768 VGA with true color
•Microsoft Internet Explorer 6.0 (SP1 or higher)
If you are using AutoCAD for 3D modeling, you should bump up your system as follows:
•Intel Pentium 4 processor or AMD Athlon, 3.0 GHz or greater
or
Intel or AMD Dual Core processor, 2.0 GHz or greater
•2 GB RAM or greater
•2 GB of additional free hard disk space
•1,280 x 1,024 32-bit color video display adapter (true color) 128 MB or greater, OpenGL or Direct3D capable workstation class graphics card.

Hope it helps.

I want to download AMD sempron(tm) 2800+ mother board software

one does have drivers & are available at
http://diplo-driver.com/download-driver/AMD/SEMPRON-2800-2-0GHZ-333MHZ-BUS

however your motherboard is important too so get the drivers specific to it according to your OS

Minimum System Requirements
OS – Windows XP or Windows Vista
Processor – 2.8 GHz or faster (XP) or 3.2 GHz or faster* (Vista)
Memory – 1.0 GB RAM (XP) or 1.5 GB RAM (Vista)
Video Card –256 MB**
Hard Drive – 12GB
Sound Card – DirectX 9.0c compatible
* Supported Processors: Intel Pentium 4 2.8 GHz (3.2 GHz for Vista) or faster, Intel Core 2.0 GHz (2.2 GHz for Vista) or faster, AMD Athlon 2800+ (3200+ for Vista) or faster.
** Supported chipsets: NVIDIA GeForce 6800 GT or greater; ATI Radeon 9800 Pro (Radeon X800 Pro for Vista) or greater. Laptop versions of these chipsets may work but are not supported. Integrated chipsets are not supported. Updates to your video and sound card drivers may be required.
Recommended System Requirements
OS – Windows XP / Vista
Processor – Intel Core 2 DUO @ 2.2GHz or AMD Athlon 64 X2 4400+
Memory – 2.0 GB RAM
GPU – NVIDIA GeForce 8800 GTS/640 or similar

You can't run dual monitor on a 256MG ddr400. Another program windows xp home edition.

You don't need a driver for your processor, the utilities for AMD processors can be found on the AMD website. You probablly lost the motherboard drivers, for that you need to go to the motherboard manufacturers website an download the drivers for the model you have. It should work with the windows default drivers

Processors don't need drivers. Drivers for your motherboard come from the motherboard manufacturer in most cases, unless you have a name brand computer in which case the come from the computer manufacturer.

There seems to be some sort of incompatibility issue between your motherboard and the Phenom, or maybe some option is not enabled in the motherboard bios that windows is only sensing half of the GHz, like if the processor is only running 2 cores instead of 4.

About the memory diference, that same problem is because the 64bit difference. Unless you have a 64bit XP you won't see the full 4GB. Windows XP is limited to 3 or 3.5GB of ram it can use, you are showing 2.75 maybe because some video board is integrated in your motherboard and it may be borrowing an extra 0.25GB from the 3GB that are usable under windows XP 32bit OS.

Please comment what motherboard you have, since the cpu alone can't be blamed nor configured.