All I want is....

[pbassred]

(since I had to buy windows7 to be able to install it) a version of Sony vegas movie studio platinum with exactly the same features, that runs in 64bit.

[TimStannard]

Somy Vegas Movie Studio (all versions) does run in 64bit Windows but it is not available as a 64 bit application.

[pbassred]

Exactly Tim!

[TimStannard]

So you've got a version of VMSP which runs in 64bit Windows, which is what you said you wanted. Oh you mean you want a 64bit version of VMSP that runs in 64 bit Windows. Why? Out of interest.

[pbassred]

To take advantage of my 8GB of memory, instead of the 2GB that a 32bit system allows.

[Stripe]

Or you could type '32bit system 2gb memory' into google and find out that...

What I understand about 32-bit OS is, the address is expressed in 32 bits, so at most the OS could use 2^32 = 4GB memory space

The most that the process can address is 4GB. You are potentially confusing memory with address space. A process can have more memory than address space. That is perfectly legal and quite common in video processing and other memory intensive applications. A process can allocated dozens of GB of memory and swap it into and out of address space at will. Only 2 GB can go into user address space at a time.
If you have a four-car garage at your house, you can still own fifty cars. You just can't keep them all in your garage. You have to have auxiliary storage somewhere else to store at least 46 of them; which cars you keep in your garage and which ones you keep in the parking lot down the street is up to you.

Does this mean any 32-bit OS, be it Windows or unix, if the machine has RAM + page file on hard disk more than 4GB, for example 8GB RAM and 20GB page file, there will never be "memory used up"?

Absolutely it does not mean that. A single process could use more memory than that! Again the amount of memory a process uses is almost completely unrelated to the amount of virtual address space a process uses. Just like the number of cars you keep in your garage is completely unrelated to the number of cars you own.
Moreover, two processes can share non-private memory pages. If twenty processes all load the same DLL, the processes all share the memory pages for that code. They don't share virtual memory address space, they share memory.
My point, in case it is not clear, is that you should stop thinking of memory and address space as the same thing, because they're not the same thing at all.

[vidmanners]

Surely the 64-bit version IS the Pro-version.?

For UK-prices like £32 for a fantastic program, OP has little to complain about.....and I thought 32-bit addressed just a tad under 4G - which is what I have - if it's only 2G I've been oversold!

pbassred: you bought v11 Production Suite, with the advantage of a 1hr Tutorial and Soundforge which I use every-so-often to play with the audio...
Do let us know how you get on . . . I found VSv10 Mighty confusing for a few weeks, but YouTube Tutorials and Help (here) improves things a lot.