Install linux (slackware) on dell laptop.
 

I have a dell laptop that came with windows 7 pre-installed.
It has 3 partitions.
One ΟΕΜ partition 39mb, one ntfs partition 218.20gb (boot, pagefile, primary), and one recovery ntfs partition 14.65gb (system, active, primary).
Is it possible to make it dual boot windows 7 and linux?(slackware v14.0)

Yes but I highly recommend you read the documentation and make a backup of your data before proceeding. Dual booting with Lilo is a very common and well-documented task.

Thanks for answering, but I really need a partitioning guide (I have found an installation guide on youtube but it starts right after partitioning).

Do you think that youtube.com is the trusted source for Slackware documentation, or maybe there is another site? :)

Is there a step-by-step guide about partitioning for dual boot?

I found this page for Slackware documentation:

http://docs.slackware.com/slackware:install

It recommends to partition using fdisk or cfdisk and then configure lilo boot loader for the dual boot. Have you used these tools before; are you clear on these concepts? If not, do you know how to use man pages? Do you have a specific question/error message that troubles you (or just sort of generally lost)?

I would recommend you do as much reading as possible on this, but also -- if you're familiar with downloading ISOs and burning them to disc -- get yourself a copy of this:

http://www.sysresccd.org/SystemRescueCd_Homepage

It can not only help you partition your drive (in a pretty easy-to-do visual way) but it can save your system if you muck things up (as I definitely have from time to time).

/Glenn

Several years ago, I did a series of posts on installing Slackware at a blog I was volunteering at.

This link points to the last post; it links to the others. Number two in the series illustrates partitioning.

The pictures aren't the best, but I hope it will help.

I prefer cfdisk; I find it much friendlier than fdisk.