Consider reinstalling Windows 7 32 bit with the license key on the COA sticker on bottom of laptop. You are entitled to use either 32 or 64 bit with each license.
Check the Acer SUpport Downloads webpage for your model computer to make sure 32 bit
drivers are available, although most all with be in installer or arrive quickly via Windows Update.
If you can borrow or find a 32 bit installer, we can help you unlock all versions if necessary so you can install your licensed version.