I just purchased a Windows 7 32 bit DVD and it's shipped, on way right now. But my friend told it's not receive enough 4GB RAM I have on my laptop. And only Windows 7 64 bit can. Is it true ?

yeah but it will only find and read/use 3.4gig must have 64bit to use 4gig or higher. Later---

So if i want to upgrade my RAM to more, i must to buy 64bit version ?

Yes I run 64bit for that reason Later---

If you are using a 32-bit version of Win 7 you will not be able to use over 4GB and the one you ordered will not use all of the RAM either.

You may want to check if you can actually increase the RAM for your laptop; if you can't its not much loss, a 64-bit version would be better if you can you may want to try and exchange it but I wouldn't pay much; perhaps pay shipping back and forth and get them to knock off what you paid for it off a 64-bit version.

If you you don't use your laptop intensively then there may not be need for the extra RAM. It's your decision.

- Let us know how it goes.