Laptops overheat easily. They have very small fans and the manufacturers do everything possible to reduce current consumption to prolong battery usage and keep the computer small. Under this circumstances I would suggest the following in addition to vents cleanup and volume reduction:
1: Reduce to minimum the programs in Startup Menu. Click Start > Run. Type: msconfig and press Enter. Check Selective Mode and click Startup. Uncheck everything which is not essential (AV,for example)click OK and reboot. Please do not uncheck items that are required to the normal operation of the computer (touch pad, wireless etc.)
2: Make sure that there is enough space below the computer and that there is free circulation around it. You may lift it up a little on books or something to ensure enough space at the bottom.
3: Consider buying one of those special devices that have fans that cool the bottom of the laptop when you place it on the device.