It's just possible that your Vostro 1700 will actually take 8GB ram, but probably not worth trying.
There are some chipsets of that era that are documented as having a 4GB limit but actually will take 8GB, a friend of mine has a very similar Dell delivered with Windows 7 that he has upgraded successfully, it's even running Windows 11 now!
That said, it's almost certainly not going to be cost-effective, that model (I think) takes DDR2 ram and you'd need a pair of 4GB sticks that are as rare as rocking-horse poo and extremely expensive if you can find them.
