If it's a brand new build then 75C is normal, until the thermal pad or thermal compound sets. If it's not a new build, the you should remove the HS&FAN... Completely clean the CPU of all thermal material and apply some Arctic Silver 5. Use about a grain of rice worth and spread it evenly over the CPU die with a credit card or "like" object.
Then give it 100 hours to set.
Also, i you're using the stock HS&FAN... You might wanna grab an after market one, Possibly a Zalman or Thermaltake.