1. Win --98 or Xp or Linux.... Apple----- which is the best..??
For Windowns, 98 is NO longer available. ALL desktops and LAPTOPS now come with Windows XP. Windows XP Home Edition should suffice. You usually have Windows XP Professional as an option, but it is more expensive, and you really don't need it.
2. Processor--Intel[ P 4 or P 3.? ] ---AMD, any other -----Which among are the best.?
Well, the thing with processors and laptops is that the higher the processor speed, the thicker the laptop (and most likely the heavier the laptop). You said that you wanted a "laptop, desktop", does that mean you want one of those laptops they sell, but are so thick and heavy, that they might as well be desktops? If that's the case, then I guess you won't have to worry about processor speed too much (if you don't plan on carrying it around all the time).
I think laptops use the intel centrino technology. Mine is a Pentium 725 1.6 ghz processor speed. It's slower than my desktop, but still does it's job. I only like it cause it's thin. If you don't mind a thicker laptop, you can get a processor speed that's higher; in fact it may even be cheaper (i've noticed the thinner the laptops, the more expensive they are, even though processor speeds for thicker laptops are higher).
3. RAM--- 256 or 512 or more than that.....??
I would just go for the lowest one that they give you and buy it separately yourself. It's much more inexpensive that way. If you're gonna buy ram separately, I would go for a Kingston.
4. Hard Disc Drive---20 Gb or 40 Gb or 80 Gb or more than that...??
My lappy is a 40 gig, and so is my desktop. Iw ould probably see if you can find a computer that includes a 40 gig hard drive. If you want more memory, you can buy it separately as well. Western Digital and Maxtor are good brands if you're going to buy more hard drive separately.
5. CDROM Drive---- which is the best
I would go for a DVDrom drive instead. Don't think brand name matters too much for this....though I could be wrong.
6. Dvd Writer-- which is the best...??
Not too sure about this, but I don't think a DVD writer is needed for dental school. HOWEVER, if you do get a dvd-rw drive, you DO NOT need an extra CD ROM. A DVD-rw drive does it ALL for you: it can write/read dvd's, write/read cd's. So it's basically a CD-ROM, CD writer, DVD-rom, dvd-writer all in one. Not sure about brand names though.
7..Any other specila softwares....???
Make sure your laptop comes with Microsoft Office. Anything 2000 or later should be good. Microsoft Office Small Business Edition probably has everything you need: powerpoint, microsoft word, microsoft excel, and some other stuff I can't quite remember (but those three are the main things you probably want. Microsoft Office Basic Edition is their cheaper package, but unfortunately, it does not include powerpoint. If you know someone that perhaps has powerpoint, perhaps you can borrow it from them and get the office basic edition.
You also want to make sure you have Adobe acrobat, but that of course can be downloaded for free from their website if the laptop or desktop doesn't come w/ it already.
ADDED:
Just to let you know, if you can see if an internal wireless network card comes with the laptop. If not, you can go and buy an external one separately, but I've been told an internal wireless PCI network card gets better signal because it actually uses the lcd monitor of the laptop as an antenna, where as the external PCI card is just this small card sticking out beneath the keyboard of your laptop. Um....this is if your school has a wireless network. Might want to check on that.
Hope this helps!
