I'm fairly sure that Visual C++ has some registry keys that are set upon installation that are required for it to work correctly. Also, I don't recall seeing an option for the location of where it should be installed to.
I know wxDev-C++ has a mobile version. It's not pretty, but hey, it works.
Another alternative is Eclipse with the CDT plugin and MinGW compilers, but that requires that whatever computer you run it on also has a Java Runtime.
g++/gcc is the GNU Compiler Chain for C/C++. It is not a separate programming language. So no, there is effectively nothing to relearn as far as writing code is concerned.
g++ is the C++ compiler included in GC- ah. jRaskell beat me to it by a long shot. It's an excellent compiler: fast, cross-platform, and I just love it.
i installed dev++ on the usb 2gb its an allright program but i like the look and feel of vc++ 2008 but when im on the go this will have to work. thanks for the help guys
@ Bazzy: Thanks for the info.
@ Albatross: is MinGW & Code::Blocks linux downloads only cuz if they are i won't beable to use it?
@ Bazzy: what is 'IMO' and thanks for saying that codeblocks is easyer then VC++
@ Firedraco: please explain what you mean by command line arguments