Unhappy [Q] Thunder cannot enter Recovery Mode for ROM update

I am not able to enter into recovery mode to upgrade my ROM pls help me solve this out as my HTC thunderbolt has gone slow and showing error msgs now and then.

I have tried all possible way to open the Recovery mode by pressing the power and volume keys using apps like Rom magaer, 4txt recovery etc but same everytime i try to update my phone just have a normal restart thats it but new ROM cannot be installed



Please help me guysss



Please share you views about this issue and help me solve it...