You are strongly advised using these sites. The upload source for these files is often listed vaguely as "search engine". There is no verification that these files are authentic, safe, or that they contain a legitimate 64-bit driver. Downloading and running unverified executable files from obscure driver download websites is a primary way to infect your computer with malware, adware, or viruses. Given that a safe, proven, and reliable solution like VueScan exists, taking such a risk with your personal data and PC is completely unnecessary.