Doddy, great link, thanks.
I think I should be able to add grease nipples to the end of the blocks as shown in the manual which looks the simplest method.
However I have not been able to find anyone who sells them separately yet. Found a company selling loads of different ones but couldn`t see the thread size of them in the hiwin document.

Clive S, thanks for the info on bearings, I think they are BK17 as 25mm screws. Glad to know you can change the bearings without getting new blocks which may save a few quid, I will take one off when I get time and have a look.
As for the computer I have had a wiggle with the connectors etc and blown all the dust out with an airline. Tried a CD with the recovery part of XP only ( no original disk) but it wouldn`t have any of it. I will see if my brother can help as he is very good at IT stuff.

I am thinking of getting a UC300ETH-5LPT ethernet motion controller which I hope could be installed with everything else in the control box remaining the same. ie between the PC and the BOB .
This means that it wont matter what computer I use in future.
I am planning to use fusion 360 for cad/cam (its free and powerful ) but it will only run on 64bit systems. Also moving forward more and more software is going to be like that.

It seems like the uc300 eth was made for UCCNC initially and has a plugin for mach3/4. As I will need to learn from scratch anyway (assuming the pc is dead) might it be better to just get UCCNC and learn that. I know mach 3 has huge user base and more history so might get easier support. Any thoughts?

Thanks

Ollie