I built a computer in hardware class and the mobo our prof got us is a MSI K8MM-V. It is a socket 754 with a Sempron 64 bit processor. My question is this:
Is this mobo okay enough to try to get a better processor for, or should I instead replace the mobo with a better one? I know the 754 is kind of old technology, so I'm just wondering what to do. thanks,

Well, I would suggest upgrading your motherboard, because the best 754 socket CPU you can get is a AMD Athlon 64 3000+, but they are no longer being made. Instead I suggest that you purchase a new motherboard with a 939 socket. For your CPU I would suggest a AMD Athlon 64 3200+.

AMD Athlon 64 3700+ for Socket 754 is the best.

Indeed but they are almost impossible to find. You can always try to use a Turion-64 cpu on it (if the motherboard supports it) as they up to 2.4GHz. They do not come with a heatsink/fan though so you'll need to buy one too.

that board and CPU are nothing special, but it may be fine for you depending on what you want your PC to be able to do. If you just surf the net/email/etc ,then you'll be fine with what you have. If you want to play new games/multitask/number-crunch/etc then you'll need a better setup.

Since you were planning to replace the processor anyways, then get a socket939 board and a socket939 processor. 754 does not support dual channel memory configuration and limits your upgradablity. also that mobo only has an AGP slot for video expansion which will further limit upgradability.

If I replace the board, will I need to reinstall the Operating systems? I have Windows XP and Mandriva Linux, so will they still work with a new setup? Also, what is better about dual channel and how can you tell if the mobo will support it? I also thought that AGP was the way to go, but obviously not. What is it now? I guess my main question is if I need to reinstall or not. I would rather not if it can be avoided.

1. you will have to re-install if you want a stable system. sometimes XP(SP2) will work on a different system without doing anything to it, sometimes you perform a "repair" instal to overwrite system files, but the best way it to format and clean install.

2. in single channel memory mode, a second RAM stick is not used until the first stick is maxed out (which is not very efficient). in dual channel memory mode both sticks are utilized at the same time (basically commands waiting to be executed do not have to wait for the previous command before it can start, think of it as: single channel= long line of shoppers and only one register open... dual channel= same shoppers but two registers open... the latter is more efficient)

3. Its not a question of the mobo supports it or not, the mobo doesn't really matter because AMD K8 processors have the memory controller built into the CPU. socket754 only supports single channel, socket939 supports dual channel (which is why it needs the extra pins)

4. AGP was the way to go years ago (AGP has been around since the PentiumII days). PCI-E is the current standard. you can still get some very nice AGP cards, but the interface is being phased out. most socket939 boards and probably all of the AM2 boards will have PCI-E as the video standard.

thanks for the info. I'll be looking around for a sweet mobo to upgrade to, but in the meantime, I guess I'll have to make do with my present one. I'm looking for a good one, so I'll keep what you said in mind. thanks