New processor for my compaq presario sr1810nx

You can get all the specs from here: Compaq Presario SR1810NX Desktop PC Product Specifications

Yes. Up to 2GB officially, 4GB unofficially.

connect the cable of the motherboard properly and replug the RAM.

The mother board will support any Socket 939 AMD Athlon X2 Processor upto the 4800+ model.

However Socket 939 Processors were discontinued so you may have a hard time finding a "New" one.

Compaq Presario SR1810NX Sempron 3200+ 1.8 GHz ...

Bad Power Supply. Weak Voltage power rail.

Not enough power to turn the Processor on, and keep it on.

1) ALL those LED lights together, use less than 1 Watt of power.

2) EACH fan uses 2 to 3 Watts

3) A typical Processor can use 51 to 125 Watts. Depends on what Processor it is. (Older Processors use less Wattage)

The Compaq Presario SR1810NX desktop computer, comes with an AMD Sempron 3200+, processor.

(Uses the Socket 939 processor socket)

[Maximum operating capability is a 1.8GigaHertz frequency rate.
1.8GHz

Giga = Approximately 1 Billion
Hertz stands for Cycles per Second.
Frequency Rate is correct computer speak for 'Speed'
The AMD Sempron 3200+ processor, can operate at a maximum frequency rate of 1.8 Billion Cycles per Second ]

HP Support >Compaq Presario SR1810NX desktop computer > Product Information > Product Specifications,

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00609384&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&product=1841795&lang=en

The AMD Sempron 3200+, can use up to 62 Watts,

http://en.wikipedia.org/wiki/List_of_AMD_Sempron_microprocessors#.22Palermo.22_.28Socket_939.2C_E3_.26_E6.2C_90_nm.29

(Palermo Core)

When you press the plastic Power On button, you are contacting a Power On switch inside it.
(Typical ATX Power On switch,

http://www.directron.com/atxswitch.html )

When an ATX power supply is plugged into power, there is a 5 Volt Standby power, present inside the power supply.

Pressing the momentary contact power on switch, closes a circuit that directs the 5 Volt Standby power to 'excite' the power supply, and turn it on.

The first chip to receive power is the BIOS chip.
[Chip and Chipset are slang terms for I.C.
Integrated Circuit.
BIOS stands for Basic Input/Output System]

BIOS,

http://en.wikipedia.org/wiki/BIOS ]

BIOS looks to see what devices are installed, does a Ram Memory count, TURNS the Processor on, and hands the computer over to the Operating System.
(Windows XP is one example of an O/S. Operating System)

The LED lights receive power, so do the fans, and the Harddrive. When it's time for the Processor to kick on, there isn't enough power, and the Power Supply 'falls to it's knees'.

Replace the Power Supply.
It's just one of the basic ATX power supply's that are readily available in a multitude of places.
The Wattage is 300 Watts.

The ATX form factor for this power supply, (Size and shape), is approximately 6 inches Long, 6 inches Wide, and 3-1/2 inches Tall.

Power cables needed:
(Continued in a Comment)

If you want to run Windows 7 on your PC, here's what it takes:

• 1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor
  
• 1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)
  
• 16 GB available hard disk space (32-bit) or 20 GB (64-bit)
  
• DirectX 9 graphics device with WDDM 1.0 or higher driver
  

usually like this:
Details of - COMPAQ PRESARIO Laptop - Celeron 1.7 Ghz - C501
Main Features :

• Intel Celeron- M 420 (1.73 GHz)
• Intel 940GML Chipset
• 1 MB L2 Cache
• 256MB DDR2
• 80 GB HDD
• 24X CDRW/DVD Combo drive
• 15.4" Widescreen WXGA TFT BrightView
• Altec Lansing Stereo Speakers
• 56K Modem
• Integrated Wireless LAN 802.11 b/g
• LiIon Battery
• TouchPad
• S-Video TV Out
• 2 USB 2.0

You cand put extra memory until 2 GB RAM but i see no use of it.
1GB RAM work excellent under Winxp
Also, you can get a better hard drive (160 GB).

the requirements are


FOR WINDOWS XP

• Windows XP (Service Pack 2)
• 2.0 GHz P4 processor or equivalent
• 1 GB RAM
• At least 6.5 GB of hard drive space with at least 1 GB additional space for custom content
• 128 MB Video Card with support for Pixel Shader 2.0

FOR WINDOWS VISTA

• Windows Vista (Service Pack 1)
• 2.4 GHz P4 processor or equivalent
• 1.5 GB RAM
• At least 6.5 GB of hard drive space with at least 1 GB additional space for custom content
• 128 MB Video Card with support for Pixel Shader 2.0

For computers using built-in graphics chipsets, the game requires at least:

• Intel Integrated Chipset, GMA X3000 or above.
• 2.6 GHz Pentium D CPU, or 1.8 GHz Core 2 Duo, or equivalent
• 0.5 GB additional RAM

So what does your computer have?

This is just a rough guide, as it all depends on the the games your looking to play, but this is about normal to get games running without problems :

MINIMUM SYSTEM REQUIREMENTS: 
Microsoft(r) Windows(r) XP Service Pack 2, Vista 
• 1.8 GHz processor 
• 512 MB RAM 
• 8 GB available hard drive space 
• 128 MB video RAM or greater, with DirectX 9 Vertex Shader / Pixel Shader 2.0 support 
• Sound card, speakers or headphones 
• 56.6 Kbps Internet connection required. 

RECOMMENDED SYSTEM REQUIREMENTS: 
3.0 GHz Intel or equivalent AMD processor or better 
• 1 GB RAM or better 
• 10 GB available hard drive space 
• 256 MB video RAM, 
with DirectX 9 Vertex Shader / Pixel Shader 2.0 support (Nvidia 6800 or better) 
• Internet connection with Cable/DSL speeds 
Note: recommended specifications provide optimal experience for single player and up to 4 player/medium size map multiplayer.