I have a pentium 1.5 GHz(850 chipset machine) with a 40 gb hard disk.I tried installing nt server 4.0 on it. but after completing the ms dos portion of the setup it asks to restart the computer.I did this but after restarting the computer i get a blank screen with a blinking cursor and it appears to hang.I tried to check my c drive and it shows me the winnt temporary directory.I have only got the c drive the rest of the space is unpartitioned.what should i do

It is normal that the rest of the space of the hard disk is first forgotten. When NT4 was released, 40 GB HD didn't exist. When you will be ready with the service pack, with disk manager, you 'll see and format the rest of the disk. Now, for your blank screen...

http://www.windows2000faq.com/Articles/Index.cfm?ArticleID=13894 deals with installing NT (workstation/Server) to drives larger than 7.8/8Gig. You need the updated ATAPI.exe - part of SP4 and later. John Savill's article (FAQ) details it all for you. Worth knowing about his FAQ site at: http://www.windows2000faq.com and also other resources at the parent site (win20000mag.com) - especially the IT Library.

The easiest thing to do would be partition the hard drive during setup and make the bootdrive C: no more than 2Gb. the rest (after installing SP6a just have as a nice big D: (it keeps things tidier)