when double clicking the egg timer goes for a second then nothing. When viewing the process tree the iTunes processes have started but the program has not, nothing in applications etc.
A couple of questions by way of narrowing in on possible culprits. (Neither suggestion is intended as a cure in itself.)
(1) Does your QuickTime Player launch, or do you get an error message of some kind when you try to launch that?
(2) Try (by way of experiment) disabling the BonJour Service.
In your Start Menu, right-click Computer and select "Manage".
Expand "Services & Applications".
Open "Services". (Maximise the window to better see what's going on.)
Right-click the BonJour Service and select "Properties". In the "General" tab, set Start-up type to "Disabled".
Restart the PC, and try launching iTunes again. Does it launch this time?
Nice suggestion on Bonjour the blooming thing! Disabled that and it works.
By any chance, do you have a recent version of IOBit's Advanced SystemCare installed on the PC, Pegs? If so, try uninstalling and reinstalling that. Can you launch iTunes without having to disable the BonJour Service now?