Does modem affect the download speed of the internet?

Absolutely! The maximum speed will be divided into even parts for all users. For example: accessing the internet with 768kbit download and 128kbit upload (which is a standard DSL speed here in Germany) with 2 PCs and one router, both PCs will get half of the maximum, but only when both use the internet at the same time. Inbetween one of the users will be able to get the maximum speed. There are ways to control the ratiOS the users get (i.e. using a proxy). ==Correction== The ONLY time you will notice any major change is if either PC is using NEAR the maximum connection speed. Visible speed changes will be noticed with some larger file downloads, from low traffic sites. Running speed tests from two networked computers (different speed test sites) has yielded only moderate reductions (< 50%); and these are very bandwidth intensive connections. For normal web Surfing, little to no difference would be noticed. Bandwidth is not, typically, divided; but used as the request received by the modem. Therefore, the bandwidth of the site(s) you are hitting will play a major role in determining which PC gets the faster throughput. Also, the lower the maximum speed available, the greater the difference seen will be. 2 computers sharing a dial-up connection would effectively halt communication on both PCs.