I've just completed a new linux installation, de-selecting many X packages from the installtion window.

Now i want to install the X packages and some other packages as well.

Can i do it getting the same window whihc is displayed during installation.

Installing individual rpm is too time consuming.

No you won't get that window again, there's an X-based utility "Add/Remove Packages" that provides a graphical interface for adding/removing packages, but since you don't have X you won't get that

Maybe, you can try to upgrade, but that'd take even more time than a fresh installation.
If your network card is working and you have a decent internet connection you can use tools like yum/apt-get/synaptic to automate the process of installing the packages over the internet.

But I guess, the best option is to install X manually. Don't fret, you'll find all the 'x' rpms beginning with "x-something", also the rpm will tell you what all dependencies you require.

Hope this help!
regards,
koodoo

Just a hint:

You should always tell, which distribution you're using, while there are different ways to add/remove software.