IDE causes high cpu / fan usage

I cannot see all your running processes including any hidden ones.
I dont have a benchmark for your computer.
I havent done a security sweep (in depth) of your computer
Nor have I done a comprehensive cleanup for you.
Not being pedantic here just pointing out how hard it is to judge what is and isnt without all the details.
AFAIK 30% could be normal for your system Richard

Could you possibly do a basic speed test with NOVABENCH and post that here then do the following.

A restart between each step may be useful but usually only needed after running WISE

  1. Remove any unwanted software and toolbars etc.
  2. Go HERE and get CCLEANER and install and run it once at its default settings. (get the free version)
  3. Go HERE and get WISE Registry cleaner and run it in DEEP SCAN and let it do its thing.
  4. Run CCLEANER again.
  5. Restart the computer.

Re-do the speed test and post it.

The next section is up to you but I do reccomend it when I see consisten high CPU usage for no real reason.

a. Run the ESET online scanner until completion and fix any issues it may find.
b. Install Superantispyware and run it and fix any issues it may find (FREE version)
b. Download and run MBAM and fix any issues that may find (free version)
c. Run CCLEANER then WISE REG cleaner and restart.

Redo the speed test and post it.