Change from a 32-bit to a 64-bit in windows 7

when i bought my computer i was given the choice of using a 32-bit mode or a 64-bit mode, i picked the 32 because i was unsure of which one to use, but now i realise the 64 bit would be better for me because i need to use CAD and other applications like it.
i want to know how to change it and also if i will lose the programs i have loaded on already?
thanks

I suggest a clean reload of the O.S. When I've done an upgrade in the past it leaves a mess that takes up lots of HD space and to me is just an eyesore everytime I look at my C drive contents.

But, you can do an upgrade and migrate some of your stuff - but not your installed programs.

Here's a blog post that has more details.
http://blog.taragana.com/index.php/a...-to-64-bitx64/

Cheers!
Greg [MSFT]