Okay, here is a list of steps that install vmware-tools on Slackware 12.1
You need to install PAM before proceding the instruction, get PAM from LinuxPackages.net & install it
(http://www.linuxpackages.net/search_view.php?by=name&name=pam&ver=12.1)

 After that, do:

1. cd /etc/rc.d  
2. for V in {0,1,2,3,4,5,6}; do ln -s /etc/rc.d /etc/rc.d/rc${V}.d; done  
3. mkdir /etc/pam.d  
4. cp /etc/rc.d/rc.inet1 /etc/init.d/network  
5. cp /etc/rc.d/rc.inet1 /etc/init.d/networking
6. In VMWARE, select Settings => Install Vmware Tools
7. $mount /dev/cdrom /mnt/cdrom
8. cp /mnt/cdrom/vmware*.tar.gz /tmp
9. cd /tmp
10. tar zxf vmware*.tar.gz
11. goto the extracted folder and $./vmware-install.pl  

Well, it took me some time to change, so I just noted it here for my own reference or anyone who have the same trouble like mine

I appended “vga=791″ to the kernel line in /boot/grub/menu.lst and voila .. it worked as expected: my 1024×768 resolution

Here is the list for you to refer:

Colors             | 800×600   1024×768   1280×1024

256     (8bit)    |   771        773        775
32K    (15bit)   |   787        790        793
65K    (16bit)   |   788        791        794
16.7 M (24bit) |   789        792        795