Dell Optiplex GX 260 Processor upgrade

[wagtail757]

HI

I have a small prob with my pc. It is fairly old and as a reult a tad slow, i have upgraded bits and pieces and decided to upgrade the processer i found a website called inspecs that told me what my system contained and what are compatible upgrades. selected a processor and ordered it when it arrived i installed it and to my dismay nothing happened apart from the normal green power light was orange, but that is all it would do. Have i done somthing stupid or is there somthing i don't know about. I haven't got the best knowledge about computers and am trying to learn as i go along, if anyone could give me some advice or pointers i would be very greatful.

the processor that i have bought is
Intel Pentium 4 P4 2.8 GHz CPU. Socket 478 1M / 533


and my specs are

System Info
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Model : Dell Computer Corporation OptiPlex GX260
Chassis Type : Mini Tower
Service Tag : GKMBG0J
Operating System : Microsoft Windows XP Professional Service Pack 2 (Build 2600)

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Processor
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Number Of Processors : 1
Type : Intel Pentium 4 1800 MHz
Processors Bus Speed : 400 MHz

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Motherboard
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Manufacturer : Dell Computer Corporation
Model : OptiPlex GX260 Rev. Not Available
CPU Slot/Socket Type : Socket 478 mPGA
Chipset Vendor : Intel i845G Rev. A1
Bios Manufacturer : Dell Computer Corporation
Bios Version : A09

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Graphics
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</FONT>Model : ATI AGP Radeon 9600
AGP Speed : Not Available
Monitor : Plug and Play Monitor

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Storage
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Hard Drive 1 : WDC WD400BB-75DEA0
Size : 38.15 GB
Hard Drive 2 : WDC WD400EB-00CPF0
Size : 38.17 GB

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Memory
​

Total RAM Installed : 1280 MB
Type : DDR DIMM PC2100
Used RAM Slots: 2 of 2

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