porky

Can anyone help please ? I have a PC running XP. Out of the blue I am loosing connectivity. I fire up the PC and connection to my LAN/ Router doesn't work. I have tried checking the hardware and all reports are that it is working correctly. I then delete the NIC driver and reboot. The system spots the NIC and recognises it as new hardware and automatically installs the driver. Connectivity is then fine and everythng works fine until the next timer I power up the PC. It then has no connectivity and I newed to repeat the whole process. I have swept for viruses before and after installation of the NIC, with no results being returned. I still have a hunch that the problem is virus related but cannot now think of what to do next. Has nayone any thoughts that might assist in clearing up this problem ? Porky