Slow PC-what next?

Hello there,

I have an HP 655 to which I added Ram. I now have 6,00RAM (5,60 GB still to be used). I have Windows 7 Pro. 

My problem: the PC is slow (even after having formatted it). For instance, it takes ages to open Trados. 

Question: do you guys think things would get better if I added an SSD disk (maybe 240GB)? [I spoke to a technician who said the speed will indeed increase, but I'd like your opinion (cause he's the one selling the product&installing it... so of course he's depicting this thing as being good...).]

My concern: I'd rather not waste money and just purchase a new faster PC if any of you experts tell me not to add SSD. In that case, I've been told a Dell would be great for the type of work we (translators) do. Pls advice. 

Pls note: I have worked for yrs for big companies using Dell or Lenovo. Never had a problem. This new PC is needed now that I've gone freelance. I'm asking cause I'm a Mac person, but of course cannot use Trados on Mac (bon, yes, but that option b. is too complicated). 

Thank you for your answer.

Bye, 

Rosaria