Thanks for the input, guyin916!
Yes, according to the product manual for the Compaq C300 series and the HP G3000:
■ The following processors, varying by computer model:
❏ Intel Core Duo T2250 (1.73-GHz), T2300 (1.60-GHz),
or T2050 (1.60-GHz)
❏ Intel Celeron 430 (1.73-GHz) or Intel Celeron 420
I quickly discovered that the Core Duo CPUs listed above are not widely distributed. I can't find any of them on the secondary market, although HP appears to offer them as parts, but at very high prices.
Some of those CPUs don't even appear in Intel's usually very helpful Processor Spec Finder (processorfinder.intel.com). I did, however, find their specs in a different part of Intel's web site as a PDF: (www.intel.com/products/processor_number/proc_info_table.pdf
After researching the 945GM chipset used in these notebooks, I assumed that my C301NR would support a CPU with a 667-MHz FSB, so I bought a T2500 (667/2.0). It is beginning to appear that the C300 will support only a 533-MHz-FSB CPU, which one writer called "unusual" when reveiwing the C300 a few months ago.
I e-mailed HP/Compaq support and asked very directly what upgraded CPUs the C301NR would support. Their first (and fast) reply was (excerpt): "I would like to convey you that the upgrading of the processor is not possible in the notebooks because of its compactness."
When I replied as asked for clarification (I mean, really, "because of its compactness?"), I received another quick reply (excerpt):
"The processor upgrade is not supported by the HP."
The C301NR is a "value laptop," I know. That's why I bought it, but intending to eventually upgrade it. (Aside: I got it at a Fry's door-buster promo for $399!) Having completely disassembled it for the unsuccessful CPU upgrade, I see that the System Board is not a genuine Intel board. (Sorry, I forgot to write down what appeared to be the mfr.)
It's becoming clearer to me that it's going to be difficult to upgrade the CPU. My next step is to keep searching for a Core Duo T2250 (533/1.73) on the secondary market.
I have no qualms about flashing a BIOS, but all members of the C300/G3000 family appear to share the one and only BIOS version (F.05, sometimes listed as F.05A, but with same date). I am not prepared to hack a BIOS, but I look forward to hearing from anyone who does so.
To wind this up, I will state just for the record that the C301NR with the 533-MHz-FSB Celeron M will, of course, utilize 667-MHz DDR2 RAM (I forget the PCxx00 spec for 667 RAM).
And it also runs Windows Vista RC2 with only one "uknown device," which I believe is part of the ACPI. "Glass" effects are not available, and I have not tried the "Glass hack" that is widely available.
One last comment: The Product Maintenance Manual (http://h10025.www1.hp.com/ewfrf/wc/m...289279&lang=en
&) is helpful. Not as detailed as Lenovo's manuals, but the disassebly/reassembly procedure is not particularly difficult, although the "switch cover" resists removal to the point of making one worry that it will break while being removed.