Can you combine pc memory ram... say if i had a 32 mb ddr ram...and i bought a 128 mb ddr ram could i combine the two...how many memory slots does a standard cpu hold?...thanx

It depends on the Motherboards specifications. Boards have between 2 and 4 memory slots and most will accept different capacity memory sticks provided they are the same type, ie you can't mix DDR with SDRAM.

On a couple of older PCs I have had odd combinations like 16meg & 64meg in a 486 and 256meg & 128meg in celery 433. In both I had to juggle the memory sticks around to find the slots that everything was happy with.

Boards also have a maximum supported memory and a maximum memory stick capacity, so check your board manufacturers web page to find if it will support 128meg dimms and 160meg total.

What do you have at the moment?
You cannot run different ram speeds either or it will run at the speed of the slowest.
Does your mobo support PC100, PC133, PC1600, PC2100, PC2700???
If you have 32Mb ram now it ain't DDR.