OK, I have a few suggestions & a few questions for you :
Firstly, the cpu temp is reported as 54C. Is this the temp your cpu normally runs at most the time? What sort of temps does it reach, e.g when playing games etc?
What cpu do you have? (e.g Pentium 4, Athlon etc)
Speedfan reports only one fan (cpu fan), or at least only one fan that is connected via the motherboard header. Do you actually have any case fans (excluding PSU fan) or not?
Re. fan speed - your cpu fan is reported as running at 100% so no, you can't speed it up anymore unless you buy a different, faster fan.
If the answer to Q3 was no, then you may want to consider adding a couple of case fans. You'll need to open up the computer & have look to see where you can add case fans. Ideally one at the back & one the front. Fan mounting places will look like round or square grills cut into the case with four holes round the outside for screws. You'll also need to measure the grills to make sure you buy the correct size of fan. Measure the distance between two of the screw holes - this will normally be 8cm, but can be 6cm or 12 cm as well. If you are able to add a fan at the front & one at the rear of the case, then you need to orientate them so that one blows inwards & the other blows out.
Another factor in cooling is airflow. If you have lots of ribbon cabling in the case, try & tidy the cables up so that they don't restrict the air flow through the case. You can do this with by using special clips that stick to the case & clip cables out of the way. Don't bend or fold sata cables though - firstly they are easily damaged & secondly they don't restrict airflow much anyway because they're thin & rounded.
Also, consider where abouts the case is placed. e.g if you have the case under a desk & squashed into a corner with the rear of the case very close to a wall, then the airflow will be reduced. The case fans & vents need to have space around them to allow air in & out. Also make sure you don't position the case near a radiator or other heat source.
Another way of keeping the cpu temp down, is by reapplying a good quality thermal paste. Ask for further instruction on this though before attempting to do it.