Hi I have a celeron 700 MHZ with 128 MB SDRAM , Those 128 MB come in one single DIMM and are installed on socket one ( I still have two free sockets ) .Now I have taking from an old PII a DIMM which is 64 MB and is Compact , My question is : can I just add those 64 MB to my memory ? is it going to work or am I going to fry my Mobo ? does it matter that this memory is proprietary memory (compact ) ?
THANX for any amnswers....

The old computer probably had a bus clock speed of 66 MHz and used 15 ns memory. Your new computer has a bus clock speed of at least 100 and maybe 133 Mhz, and requires memory that is twice as fast.

So it probably won't work.

A new 128 MB stick for your new computer can be had for about $20, so that's what I would do.