Build a computer - from PC-Pages

Use a minimum of 3 screws to put in each device, ideally you would use 4 (2 each side) but some case manufacturers seem determined to stop you doing this so fit 2 on one side and 1 on the other will be fine. If you can't get access to the back side of the floppy and/or hard drive to screw it in then you will find that the base plate that the Mainboard will fix to is removable for access purposes so take it out (it makes things easier for the next stage anyway). When you are screwing in drives then you will find two main types of screws, Coarse Thread and Fine Thread.

There are lots of differences in the screw head but generally speaking this is all irrelevant as the only thing that matters is the thread. Use Coarse Thread for hard drives and Fine Thread for CD's and Floppies. (there may be exceptions but I personally do not know of any).

With the drives fitted you can move on to the mainboard. If you haven't already removed the base plate that holds the mainboard then do so now. You can do things inside the case but it is much easier if you take it out.

Dependant on manufacturer you will have either brass pins or metal inserts or plastic spacers to fit to the base plate in order to mount the mainboard onto it. It is vitally important that when you fit them you make sure that each of them lines up with a hole in the motherboard as if you don't you are likely to end up shorting out bits of the mainboard and buying a new one.
I am reminded by this of a gentleman who came to buy a mainboard from where I was working and returned it the next day as faulty. He had a replacement and the next day he rang to say that didn't work either. I asked him to bring in the complete system to the workshop which he duly did. When he brought it in it was immediately obvious to me that there was one more pin in the back than there was holes in the mainboard and the extra pin was right underneath one of the controller pins. His wife who happened to be with him was not very amused at his efforts to fry his new mainboard and slammed the door wildly as she stormed out. Now this poor guy was clearly in for a tough time of things so I reminded him that despite man's best efforts to blow things up they do sometimes recover with time. In accordance with this and what you now know from reading the section titled "Don't be scared of hardware" I told him to leave it for a week and then try it again. Two weeks later he phoned to say that it now worked fine. Why this happens I don't know but I have come across mainboards that have been found faulty by the user, faulty by their supplier, faulty by the suppliers distributor, sent all the way back to Taiwan where it worked fine and was re-shipped back to the UK working like new. It doesn't always work like that but when it does it's a nice bonus.

So with the correct number of pins inserted you can screw down your mainboard (some pins take coarse screws and some take fine so there are no real rules here). Before you put it back in the case now is a good time to insert the processor with it's heatsink and fan and the ram. If it is a socket then you will find a lever to lift up at the side which will allow the processor to drop in easily. The lever can then be returned flat and the processor is safe and secure with excellent pin contacts.

If it doesn't drop in easily then check that you have it oriented correctly (note the orientation cutoffs below for the socket 370 pentium III). If it is oriented correctly but still doesn't drop in then check fort bent pins. If they are bent then it is quite ok to straighten them. I use an ordinary knife blade for this which I run the full width of the processor to ensure all pins are the same. Never force a processor in, as if you do you run the risk of flattening a bent pin and when the pin is flattened it is common for it to break off when you attempt to straighten it and then your processor becomes a paper weight. provided the pins are not bent flat I have yet to have a processor not work after straightening the pins.