Help! Cannot re-install Dell Support Center on XPS L502X

I had problems with Dell Support Centre (some on-screen buttons dead.) I posted in this forum was told to un-install it and re-install. I cannot make this work.

I've tried repeatedly. I get a program called aulauncher.exe This runs OK, but either does nothing whatever, or says "looking for updates", then reports "no updates available."

Please, what do I do to re-install Support Centre?

Original post: http://en.community.dell.com/support-forums/laptop/f/3518/p/19525737/20458347.aspx#20458347

Thanks

Andy

Bristol, UK