Please help!
 

Hi. I'm a new user in Linux and I have 2 questions about installing Linux on my laptop. I work with windows vista and my system is Sony,
Can I have Centos and vista simultaneously? My system is 64 bit, should I use Centos 64 or 32bit is suitable too?
Thanks

Research "dual booting" and you will find your answer -- Yes, you can run Centos and Vista on the same box. You might also want to check into VirtualBox, so you can run a windows VM inside of linux, if that is helpful for you.

The difference between 64bit and 32bit distros might cause a bit of an argument here... But, 32bit will work fine on your laptop. IMO -- I suggest going with 32bit because you don't have to deal with mixing 64bit/32bit libraries, which *can* be a headache.

1. Yes, and
2. either will work.

Note that you will need to let CentOS replace you MBR, and use the Linux boot loader to start your Windows system as well as your CentOS one. Also, you should be careful during the installation: If you pick the incorrect partitioning scheme, the CentOS installation might reformat your hard drive, wiping out your Win 7 drive(s).

You should have a full Win 7 backup, offline, before starting the installation, and make sure that there is enough free space (unallocated to any partition) on your drive. (That assumes that you're installing CentOS on the same drive as your Win 7 system. If you have a second drive available, life is much simpler.)

I would strongly recommend to try CentOS in a virtual machine, like Virtualbox or VMware. This way you don't have to mess with partitions and bootloaders andf you can run both operating systems simultaneously (at the same time). If you go for the dual boot solution you can only run one OS and have to reboot to use the other one.
If you go the virtual way I personally would recommend the 32 bit version, at least if you don't plan to give more than 4GB to the virtual machine.