ugh!! i am getting really frustrated

i have an old laptopz(xp) that i downloaded build os to because of everyone saying vista gives u problems and i can't get my phone to sync on that one. my phone tells me you need to install activesync 4.5 or higher and the disc that comes with the 6700 gives you 4.1. so everytime i try to install 4.5 it gives me a missing dll error in the middle of installation........
anyone know what the hell causes my phone to loose its connection when it enters bootloader mode on the vista pc. im about ready to shoot my computer and phone.