nazihosseinioun

i have winxp sp2. after i upgrade it. it can not go on because it sayes can not load a347bus.sys file!

the records of my DataBase repeated periodicaly & I have a field like debit which is need for a next period records which is "sum-pay". do I have to consider it as a field or not. thanks nazi

If I want my database to be in 3nf,if i add a field which is the sum of 20 fields or not.

[COLOR=#000080]if i want database to be in 3nf if i add round field (which round total amount) or not. [/COLOR]

would u please tell me when we use id column instead of combination of some columns as primary key.

would u please tell me if my erd is correct or not.

i have some tables in 2nf.now some field of "vm" table calculate based on the other fields but through a procuedre & function.not simpily add or subtracts.would u please tell me if i have to delete them in order to be in 3nf.