I'm not clear whether you have dial-up or broadband, and you don't mention your OS, or ISP. Anyway I would think that you probably have a connection weakness causing the problem and damaging your software as a result. It could be the modem that at fault, or one of the connection cables, or the power supply etc. Of course, there could be a problem with your telephone line either before it enters your house, or after. I would suggest that a start point might be if you could swap your connection hardware with a friend and see whether the problem moves to the other PC or stays with you. However, you may well need to repair Windows, and I would recommend at least SFC /scannow (with your install CD in the CD drive)once you have the different hardware available. Note - you should swap, modem, router, all cables and your splitter.