compiler trouble

i'm using a borland turbo C++ compiler on two computers, from the same disks. the problem is, on one of the computers, a can not use header files that i define; i always get the error 'can not open file (whatever).' does anyone have any idea what the problem is, or how to fix it?

also, i taught myslef C out of a book, so i don't always have an explanation for what i'm learning. this is the case in the iomanip functions,

cout.setf(ios::fixed, ios::floatfield);
cout.setf(ios::showpoint);

i know you need this code for basic output manipulation, but i don't know what it does or means. please elucidate.