Frapp, I thought of something today. Maybe you've already installed something in which case it won't be very helpful.
The one drawback I can think of with the free utilities available is they usually try to install other stuff at the same time. You get the usual agree to the conditions window, select installation directory and so on but watch out for other screens where they are asking you to install some other piece of software. The default setting is accept and install so be sure to read exactly what they're saying at each stage. You can usually decline them or un-check boxes to avoid them being installed though.
It's easy to end up with loads of crap you never wanted to install.