Inspiron 1721 running hot?

So my mom has a 17" Inspiron 1721 from like August 2007. I have been using it off and on for the past year or so, I just today got my Studio XPS 16" 1647

But anyways, her laptop seems to run a little (burning hot to me). It's not all the time, but all she did was play farmville on Facebook for maybe 2 hours, and it's burning hot to the touch. (Half of the time it was plugged in.)

It showed the cpu temperature was 70C, is this above normal for this lower end laptop? It only has the basic dual core, nothing special.

 

does the fan turn on and working normally?

if yes, it needs cleaning. Open it up and clean the fan and heatsink from dust,
change the thermal paste, then undervolt it.
You'll have a cool machine after done the above

 

70C isn't too hot unless that's the idle temperature. What you should keep an eye on is the maximum temperature - for Dell laptops I recommend using I8Kfangui to keep an eye on temperatures in the background. It'll give you the maximum temperature as well, which is more important when determining if a laptop is running too hot.

Anecdotally, my Inspiron 1520 can get rather hot to the touch even when it isn't running too hot. "Too hot" is generally anything 90 or above - you don't have to worry about damage until it hits 100 or higher, but 90 is close enough that it's best to try to get lower temperatures. And of course, the cooler the temperatures, the cooler the laptop, in general.

If the temperatures are high, or if you just want that laptop to be cooler, I would undervolt first. Search for the Undervolting Guide on this forum, and follow it. Undervolting alone can reduce maximum temperatures by 15 or 20 degrees. It also is very low risk. As a secondary measure, if undervolting alone isn't satisfactory, I'd recommend cleaning the vents with compressed air, from the exterior. This isn't as thorough as disassembling and then cleaning, but is easier and less risky. It can reduce temperatures by 10-15 degrees, depending on the amount of dust in the laptop - and it 2.5 years, you can certainly get a lot of dust. My parents' old Pentium 4 went from sometimes refusing to start due to dust causing excess heat to having no problems, all from a cleaning. This isn't to be under-estimated. Opening up the laptop is quite unlikely to be necessary. It will allow you to get the most thorough cleaning, but also carries the highest risk of harming the laptop. Whether it's worth it depends on your confidence with hardware and your ability to replace the laptop or damaged parts should something go wrong.

 

Not really risky.
Dell has perfect Service manuals for almost all notebook models in their site
meaning users who want to level up can act according to.

This one is for Inspiron 1721
http://support.dell.com/support/edocs/systems/ins1720/en/SM/cpucool.htm#wp1179839

and the result is very worthy
If I must give percentage to the cooling processes,
it's evenly spread 33.33% each between (undervolt), (cleaning dust) and (changing paste), believe me, I've been there.