Pat i downloaded v28 but from my pc to laptop I have ffor example SDATA Pc shows yes laptop shows No-Thus preventing my access database to link to sage 50

Get them to roll you back to V27.  Using multiple users on the V28 is asking for trouble.  You can have multiple users all thinking they are working on the same data but 1 person can lose connection even momentarily and you can be out of sync. Once it resyncs you have to choose who has the most important data, BUT you dont know when you lost sync and you dont know what work will be lost.

SAGE know they designed the system this way, and I was told by sage they did it purposefully (its not even a mistake, they thought this was a good idea!!). How that is acceptable and how that passed their internal thought process is beyond me. 

We are still re entering the 7 days of work from changing from V27 to V28 back to V27.

Sdata and RDA are completely unrelated - see my reply to your query here https://www.sagecity.com/gb/sage-50-accounts-and-sage-50cloud-accounts-uk/f/sage-50-accounts-and-sage-50cloud-accounts-uk-general-discussion/178671/help-moving-sage-50-accounts-from-pc-to-laptop-sdata-shows-no-after-more-stopping-third-part-access-for-microsoft-access which will hopefully address that issue.

In v27 and earlier you had to nominate one PC as the 'main site'. A machine that is always on and connected to the Internet is generally best suited for this. With v28 RDA runs on all nodes with no one site being any more special than any other one (new user permissions have been added if you want to limit what certain users can/can't do). You can certainly continue to run the server as one of the sites in RDA and continue to have users connecting to that server for the Accounts data. Having the server run RDA would not inherently cause any lock-ups, even if it is a slower machine. Obviously if it is a slower machine then this could impact on the clients in the office that are connecting to it and their access may be slower, but this would be the case even if RDA were not enabled.

Hope that helps

Thanks Darron, that is what we thought but I'm now concerned by Andrew's comment above. I'm trying to find someone at Sage to explain what is going on and will post here if I do find someone who knows.

Thanks Andrew - this is obviously very concerning. I'll see if I can find someone at Sage to comment  because it seems ludicrous for them to have done this!