@moshel
As its a system for a person who would be doing Ph.D on a filed which doesnt need heavy computer processing power, look in to this notebook model rather than a desktop...
Compaq Presario C702TU Notebook PC (GS091PA)
The base confir is,
Intel Celeron D 1.73 GHz / 533 FSB / 1 MB L2
Mobile Intel GL960
GMA x3100
512 MB <<<< Upgrade this with another 512 MB which is Rs. 800 MAX
80 GB SATA HDD
8x DVD RW drive
Wifi / USD 2.0 / LAN / Modem / Card Reader
15.4" WideScreen with 1280x800 resoltuion
with 1 GB RAM its is Rs. 24800/- incl VAT and TAX and every thing, comes free carrey case and an USB mouse...
with 1 GB its fully vista ready with GMA x3100...
as basic it comes with 1 year warrenty
but i suggest when you purchase ask the vendor to let you know whether it would be possible for you to extend the warrenty after 8 or 10 month of purchase, for information Compaq by default allows it, but some time vendors want to misguide you by stating not...
after 8 or 10 month extend the warrenty for another 2 years which usually costs Rs. 4100/- for this model