can i run ddr3 in my dellvostro 1014, i have a intel gm45 chipset
No, DDR3 is not backward compatible with DDR2. Physically it wouldn't fit and electrically there are incompatible with each other.
Check if your existing memory is DDR3 or DDR2. In one Dell manual, it says that it supports DDR2 and DDR3 but it's vague. So check what your existing memory is whether DDR3 or DDR2.