HI there, i'm just started to use red hat for my project. would you guide me how to remote access from windows client (win7) to red hat. thank you so much

you could use openssh server on the redhat linux machine and putty on the client side to access it via the command line. if your looking for a remote desktop environment though I would suggest VNC or freeNX.

SSH should be always installed on a RHEL server. Even it might be optional, so far I never came across one that didn't.
On the client side of things, "putty" or "kitty" for console and "xming" or "cygwin-x" for GUI apps ar your friends.
putty is the pretty much standard for SSHing from Windows into Linux SSH servers.
kitty is a fork which comes with a few changes, which are debateble.
Xming is a Windows X-server, which works great with putty, but only versions up to 6.0.9.31 (from 2007) are ok for free use.
cygwin-x is the x-server from the cygwin project. It is heavier than xming, but works ok in multi-monitor systems (xming has issues here) and doesn't have xming's licence issues in current versions. Cygwin as such sometime comes pretty handy anyway.

I'm kinda not understand what you guys talking. I'm really newb. Would you guide me? I'm already finished install redhat on vrtualbox. I choose desktop,not basic server

What you want to do with the server?
Why did you choose "Desktop install" on a remote vserver?
Usually this kind of servers is used to host certain services, e.g. game servers, web sites, mail server etc pp.
Knowing what to do with it will be a start to help you achieving it.

A server is like a hammer, it's a tool to do something. if you buy a hammer just to have it - fine, but if you want to use it you should at least make sure you get your thumbs out of the way undless you need a few days off at work

Howdy, I am doing this everyday, so this is how I do it:

1). On your Windows 7, get the paid version of VNCServer, use VNC Viewer from your Windows 7, make sure it is permitted by Win7's firewall
2). For RHEL, I don't know your version, please specify it next time, I'm using RHEL 6.4 as example, please go to:
System-->Preferences-->Remote Desktop, "choose allow users to view your desktop" , in the security tab, use strong password there, next make sure you open the port 5900 (tcp/dup), that is for vncserver.

Please note that the free VNC does not support encryption, that is probably OK behind your firewall, but not safe when you connect from outside (in my case, I setup port forwarding on my router, forward all outside vncserver traffic to the RHEL server), it is recommended you use the paid version. Also you can use ssh tunneling (from Centos/RHEL) so the connection is secure, I use ssh tunneling from outside all the time, RH124 book has the instructions, sorry, I don't know how to use putty to do this.

Sorry.forgot to mention.i'm using redhat 6.0 and window 7

I believe the menu is the same, correct me if I am wrong, but you should be able to do it now.

How to setup the 5900 port?

im already set the port. but i cnnot cnnect. connection time out

VNC is something you only need if you want to use your remote server with graphical applications. Is that what you want to do? Which applications do you want to use?

Why did you choose RedHat6?

Yes. I wanna remote access using gui. I choose redhat because it popular.wellknown linux distro. Or could you please suggest easy configure linux distro

Actually if you want to use GUI applications I'd rather recommend to connect from your machine to the server using ssh +X and redirect the app output to your local X-server.

RedHat only makes sense if you have a subscription as well, which will cost you a few hundred bucks per year. Without that you won't be able to get updates for your system and you'd run your system outside the licences. If you want to run something like this go for CentOS, it's basically the same as RedHat but without the licence restrictions and without the warranty of RedHat.