If you have problems with a dial-up connection to iTunes on PC
If you connect to the iTunes Store using a dial-up connection over a phone line, music previews might not sound right or might not play at all.
To resolve this issue, try connecting to the iTunes Store with an internet connection such as DSL or cable modem. If you can’t get a high-speed connection, you can still play previews in the iTunes Store.
In the iTunes app on your PC, choose Edit > Preferences, then click Store.
Check “Load complete preview before playing.”