1333 FSB processor ( E6850 ) on a 1066 FSB motherboard, DDR2 667 memory

you posted a statement of fact not a question.
it will support
not
will it support(a real question)

well NO
and NO PC stated, only mobo.(lost the PC ?)
nor that this PC was mobo bought in India?
YOUR mobo is core2, not core(tm) processor
they are not even the same class nor socket
no
here is the list of core i3 (all are LGA
your mobo is core2. (older )
all are over 1000 pins, LGA1156 (gen 0)

you can not stuff 10 pounds(or kg) of mud in 1 pound sack.
no can do.

I don't see the Gateway GT5238E motherboard supporting an Intel Core2 Duo E8400.....

The motherboard in the Gateway GT5238E has an Intel G965/Q963 motherboard chipset.
Front Side Bus, (FSB), support is 1066MegaHertz. (1066MHz)

ARK Intel G965 Express Chipset Intel 82G965 Graphics and Memory Controller


ARK Intel Q965 Express Chipset Intel 82Q965 Graphics and Memory Controller


The Intel Core2 Duo E8400 requires an FSB support of 1333MHz,


http://ark.intel.com/products/33910/Intel-Core2-Duo-Processor-E8400-%286M-Cache-3_00-GHz-1333-MHz-FSB%29


Gateway Motherboard GT5058j GT5238E GT5268E GT5436E 4006153R


(Scroll the page down)

JMHO

Regards,
joecoolvette

Sounds more like in-correct power supply ?

Yes, Johan. It is a 64-bit processor. (x64)

http://ark.intel.com/products/38512/Intel-Core2-Quad-Processor-Q8400-%284M-Cache-2_66-GHz-1333-MHz-FSB%29

http://en.wikipedia.org/wiki/64-bit

http://superuser.com/questions/179919/x86-vs-x64-why-is-32-bit-called-x86

Regards,
joecoolvette

http://en.wikipedia.org/wiki/List_of_Intel_Pentium_4_microprocessors#Prescott_.2890.C2.A0nm.29

Pentium 4 HT, Model 531. sSpec number SL9CB.

OK. So far I know you need a motherboard that has an LGA 775 processor socket; needs to support Intel processors that are Single-Core, and with an 800MegaHertz Front Side Bus.
(800MHz FSB)

Ram Memory? Dunno. K
Do know the rule of thumb is, that the Ram Memory typically operates at Half of the processor's FSB.
Therefore can only assume the ram memory is DDR Sdram, and operates at 400MHz. (PC-3200)

You haven't stated the motherboard chipset that was used, OR what computer manufacturer, and model number; this mobo came out of.
(MOtherBOard)

Also didn't state if you are using a graphics card, and what kind it is.
(PCI, AGP, or PCI Express)

This isn't a 'guess-ti-mate'. Exact specifications are required in order to replace the motherboard.
Otherwise you may not be able to reuse the Ram Memory, or graphics card. (IF used)

Awaiting needed information. Post back in a Comment.

Regards,
joecoolvette

http://www.newegg.com/Product/Product.aspx?Item=N82E16813186187

Motherboard supports Processors with a Front Side Bus (FSB) of either 800Megahertz, or 1066MHz.

1333MHz FSB support is done with OVERCLOCKING.

http://ark.intel.com/products/30783/Intel-Core2-Duo-Processor-E6550-%284M-Cache-2_33-GHz-1333-MHz-FSB%29

Intel Core2 Duo E6550 processor has a 1333MHz FSB.

http://www.manualowl.com/m/Foxconn/G41MXE/Manual/297328

I reduced the view size to 120 percent. Go to Page 27.
Press DELete key to enter BIOS Setup.

Use Down Arrow key to highlight - Fox Central Control Unit
Press the Enter key

CPU Frequency Setting should be set to 333 (333MHz)
Intel processors are 'Quad Pumped'
333MHz x 4 = Approximately 1333MHz. (1332)

http://www.foxconnsupport.com/cpusupportlist.aspx?type=mb&socket=Socket%20775&model=G41MXE&cputype=Intel

Note the version of the BIOS program also.

Regards,
joecoolvette

NOT an issue. FSB and or CPU only supports 1333 speed.

The 9600gt is as well as the 9500.

No, the one you want will not work simply because it's too powerful for the board and will not be recognized. Here you can find all supported processors
http://www.cpu-upgrade.com/mb-ECS/P4M900T-M2(V1.0).html
as you can see the only ones for your mobo are Q6600 and Q6700.

The board is maxed out at 1066 and it does not appear that gateway has a BIOS update to allow for the higher FSB reuired with the faster Intel chips. If you installed one of these newer LGA 775 chips into your computer it may work but would be a lot slower than what it is rated due to the chips multiplier would be set for 1333. I could not see any BIOS updates from gateway for this board. Also these chips are designed to run with the faster memory and the 800mhz memory speed would also be a bottle neck for your system.