quick wuestion about replacing mobo

[juiceranch]

i have a computer that was prebuilt its made by acer, i was wondering if replacing the mobo would work with a prebuilt comp, sorry, im just getting into building my own comps. im not sure if i replace it will my hd recognize it because sometimes i switch my hd with another computer and it doesnt work? does it do the same if u put in a new mobo? does windows not recognize the hardware cus when i switch hds it just shows bios and wont boot the os.

 

[juiceranch]

sorry for duble post but i wanted to say its a acer aspire t135 i upgraded the ram and the video card, and added another cdrw drive if it helps any. the mobo is a via something?? idk but the situation is that i want to switch out the case and the mobo so im putting all my hardware into a new mobo and case. i need a mobo with more available ram slots because i have alot of 512 mb ram but no like 1 gig sticks. plz help!