Hi all,
I'm planning to buy a new laptop,i need suggestions which brand is better, and what's the configuration is needed. I want to make it as a dual boot (windows & linux) at present i'm working on SAP. So that i've to practice even SAP & ORACLE both on both the Operating systems.

Thanks in advance.

That's a pretty subjective area, but I can tell you my experiences. I run a Lenovo 3000 C200 in a dual boot config between Windows 7 and Ubuntu 9ish. (was 9.04 - just upgraded to 9.10) Would I recommend the Lenovo - no. I'm not that impressed with it, but it does the job. I also have an HP/Compaq nx6325 that I've wiped and reloaded dozens of times with various Windows and Linux flavors. The only gotcha I've run into with that laptop is the Broadcom Wireless adapter. It works out of the box with Ubuntu 9.04. You have to install a driver package (available in the standard package repository) to get it working with 9.10. Any other distro I've tried (Open SuSE, Fedora, CentOS) have required a bit more work to get the wireless to a functional state.

If I were pulling the trigger on a new laptop purchase right now, I'd probably give preference to HP, but I would try to find something without a Broadcom wireless adapter.

Select a few makes that are affordable and look interesting. Then google for Linux and the name of each one in turn. If a model causes problems, you'll soon tell from the number of requests for help!

They all use boradcom adapers for the most part these days. Mostly cause they are cheep and include bluetooth with little hardware. I Have installed linux on a few HP laptops and its a varied story. The first one I installed it on worked flawlessly the second, a tablet convertible had severe issues with timing and getting hardware supported.

I have a Toshiba Tecra A8 currently running Mandriva 2009.1, and previously SLED 11, openSUSE 11.x, Debian Lenny, and Mandriva 2008.1. With the exception of Debian, wi-fi worked out of the box with no tweaking or additional work. Admittedly I didn't spend that much time with the wifi w/ Debian so...

Also, I was unable to get the fingerprint scanner working either, but I'm no secret agent so that doesn't worry me. Other than that the A8 (and presumably the Tecra series in general) are quite Linux friendly. Lastly I will add that the machine came preloaded with Windows XP SP2.

I have a Lenovo ThinkPad, R61. Wireless works "out of the box" with Fedora 10 (or greater) with no additional installation of drivers. The Fedora installer has a good, intuitive partitioning tool as well if you REALLY must use Windoze. I am extremely impressed with the hardware quality. My ThinkPad has withstood a five foot fall onto concrete, getting away with a small chip in the plastic. Display intact, and no hard disk errors at all.

I think the IBM's have that fall detection stuff built into there systems so they stop the drive before it hits the ground. :P There is some new stuff in the kernel about it recently.

If you can customize a particular brand, then look for these:
Wireless: Broadcom wireless cards seem to always be a problem, each device works on a different driver, and unless a distro comes pre-installed with firmware (rarely), you must have a LAN connection to download them.
Video: nVidia card. I have an ATI on my laptop, and I wish I had the nVidia card that's on my desktop. There seems to be a different issue with that ATI card for every new upgraded kernel.

I've noticed n Dell and HP sites, that they do not list the particular wireless cards. Usually just the type. You might try calling to find out.