Could be a number of things:
Error Message Issue:
If your running Windows XP, your going to have issues because Windows XP hasn't been supported since 2014...This means that your not going to be able to update the Operating System. This would include the update to Explorer that was loaded in 2008. Your version of Firefox and IE is old and that is why your getting the error message "Couldn't Load XPCOM", You need to update it to the current version, The Current Version of Forefox is 46.0.1. If your going to get online with this Machine and want to avoid headaches, You will have to Upgrade it to Windows 7.
System Fan Error Issue:
- Pull BIOS battery, wait for 10 seconds then replace. (you may get a message during boot that says the system time is wrong) you can just hit F2 and fix your time in the Operating System.
- Try a hard reset- Turn off the PC/ Unplug it from the wall/ Press Power Button For 10 Seconds/ Plug PC back in/ Turn on PC.
Hope this helps...