Purchaseing problem 4 to 5

Hi

Every few months I try to upgrade to  version 5 from 4.

I must have tried 5 or six times, with the same message saying the purchase site is down
at the moment etc.

I have a windows7 laptop to purchase online, with no fancy software to corrupt any procedure.

I buy online at least 2/3 times a month with no problems.

Can you please give me a clue to what may be causing the problem.

regards

John Heath

Ps. I am having to type the title blind because the window is behind the main text window.