Got a brand new emachines T3895 about 2 years ago. Wondering what I could do to fix this problem:

1. Makes loud noises, probably the processor fan. Can I replace it? and if so how?

2. Have a Celeron D processor. SO SLOW, need to upgrade it, is it save to do that? How can I?

Please respond.

Well first anything in a computer can be replaced.

To replace the fan make sure you get one rated for the processor or higher.I always go with one rated for more than what i am do this open case and you will see a fan with a heat sink below it.if you take the fan off with the heat sink which is easier you will need to clean the thermal compound off and put new do this use 50% isoprpyl alcohol and a rag.if you need to use a razor to clean off the old compound then alcohol to finish.get silver compund to put back and only put a bead about the size of a grain of far as the CPU yes it is safe to do that but make sure you find out if the mother board can take a faster CPU than you got.i looked around and couldn't find anything on that model.

Get this and run it it doesn't install scroll down to motherboard and it will tell you max cpu you can install and socket type.