What is mdworker?

mdworker is system software that takes care of spoltlight indexing. it's perfectly normal, and if this is a new machine (or a machine you've just added a lot of files to) then mdworker will be busy for a while indexing. best thing to do is to leave your computer on for a couple of hours and let it get done, and after that it will only pop up occassionaly to deal with new material.

well, there could be a lot of reasons. first thing that comes to mind: do you use fast user switching for your kid's accounts? if they've left their accounts logged in with peer-to-peer networking running that could be eating up a lt of CPU. How much memory do you have? are the vents clogged with dust? if you open activity monitor and sort by CPU usage, what processes are at the top?

You didn't answer my other questions. for instance, I don't know whether skype is running in your account or a different one.

at any rate, force-quit skype (you can do that from Activity Monitor). have you installed the latest updates with the java patches?

Fast user switching is a way of quickly moving between accounts, by leaving one account running in the background. If you always use the Apple menu, then that's not the case, so you don't have to worry about peer-to-peer (those are file-sharing programs, where people can trade things like music and movies).

you've got 2 gb of memory, which is on the low side for Lion (assuming you're using Lion). That can cause excess disk usage (and thus excess heat) because the system will be paging memory out to disk more frequently. It would be worth the $100 (or whatever) to buy a couple more gigs of ram - when I did that with my laptop the difference in performance was noteworthy. If you tell me which model MBP you have I can link you to the correct memory type and tell you how to install it.

Do your kids have standard accounts or administrator accounts? You can check that in System Preferences -> Users and Groups (that used to be called Accounts, if you're on an earlier system). You should set your kids to standard accounts if they aren't already, which will keep them from innocently installing something like MacDefender.

Did Force Quitting Skype solve the fan problem?

lol - yes, but I do have a life to live. None of us work for Apple here, so you're going to have to share me with the real world. 😝

Lion is OS 10.7, and I need the model number not the serial number. Look at About This Mac (under tha Apple menu) again. It will tell you the software version right under the apple. Then click More Info, and click system report, and on the first page (Hardware) it will say something like MacbookPro3,1. that's what I need.

I'm curious why your memory only said 2.17 G + 928 m free. you must have missed something.

what you want is pc3-10600 ddr3 1333mhz ram sticks. from what I see online you can get a pair of 4gig sticks for around $50, giving you a total of 12G memory. here's an Apple link that gives step-by-step instructions for installing it. You probably don't need that much ram, but more ram is always better, and at $50...

As far as the over-heating issue, there are a few standard causes:

• blocked air vents (which you've already eliminated), or no clearance under the machine (does yours still have its rubber feet?)
• runaway processes (look in activity monitor for any process that consistently has high CPU values. make sure you choose All Processes from the pull down menu, so you can see system processes)
• excessive disk access (4Gb should be enough to prevent excess paging, but doing something like running a movie from the hard drive, downloading a huge file, or indexing a drive might kick in the fans)

I suggest you shut down your machine and let it cool for a couple of minutes, then restart it and see if the fans kick in again. If they do, download an app called iStat and we'll look at the internal temperatures and other activity. However, fans running without an obvious cause might mean it's apple-care time.

It is possible that you have malware that is causing your computer to react the way that it is.

see this article.

http://www.inquisitr.com/206866/a-new-mac-os-x-malware-discovered/

I am trying to get rid of this malware myself.

It is possible that you have malware that is causing your computer to react the way that it is.

No, that's not likely. (In any event, this discussion ended more than 4 months ago, so its unlikely that the original poster is still listening.)

The malware you're referring to has only been seen in use as an extremely targeted attack against specific groups. It's extremely unlikely that you would actually have it, and note that the mdworker process is a normal part of the OS. Some variants of Imuler have used a process named ".mdworker", which is not the same.