Will my 56W ThinkPad power adapter NOT work with my Lenovo 3000 N100?
The manual lists three adapters. Is one preferable to another?

I read somewhere that any DDR2 of 5300 or higher is OK.
Is that the case?

Thank you

The N100 can use the higher clocked DDR2 memory, PC5400 or PC6400, but will downclock to PC5300 speed. I wouldn't pay extra for the faster memory.

I believe the N100 uses the same adapters as the T60/R60/X60, which are not compatible with the T41 and X31. They use a different tip.

There's three of the T60 adapters - a 65w, a 90w and a 90w travel adapter. The larger wattage batteries will charge your battery more quickly, but can wear on the battery more. The travel adapter has connections for multiple machines/devices, outlets and a car adapter. It's more expensive, but if you need the extra tips or card adapter, perhaps it worth the cost. They do occasionally come up in the outlet, where they're dirt cheap and basically new, but sell fast. That's were I got mine and it looked new to me.

Thanks, I got the higher powered one, an original one, on ebay.

I purchased the following from Lenovo:
2GB PC2-4200 NP DDR2 SODIMM
P/N 73P3846 S/N: L3AP789

It delivers an unsupported error.