Executable too large ?

If the exe is bigger than the amount of RAM then Windows will use virtual memory. You're a long ways from reaching that point anyways. :)
Just a little clarification. Virtual memory isn't just used when the RAM is full. It takes some of the RAM in use, copies it to the hard drive, and from there uses the RAM for the NEW application. The virtual memory is actually a copy of RAM.

6.5MB is quite big.
I don't know about that. I think something like Office (128Mb) is what I start to think of as large.

Trust me at 6.5 M there won't be much of an impact on a P-IV.

If you are really worried about it, then split your program up into smaller bits and pieces. e.g. take out pics etc and (as said) load them at run time. You can also make dlls and place your code in them. Or, you can also make COM objects.

But seriously don't stress about 6.5M.

Also, the statement "the whole program is loaded into memory" is not true. There are some very crafty and complex methods used to manage the resources consumed by applications, e.g. "path expectation" and so on. Generally yopu don't need to get your self to hung up on these details. But... what you should ALWAYS do is worry about carefully using the additional resources that you need. i.e. don't use HUGE blocks of memory unless it is justified etc.