Ip Address Changed

Something really strange happened yesterday that i have never seen before.

i had a problem a while back with a hacker from the Philippines and i thought i had got rid of him it came in with Skype, i logged on to skype yesterday and my internet security (F_SECURE) went crazy telling me i had a Trojan i noticed there was a call from the Philippines i had not intension of opening it but when i tried to delete it the computer went nuts it started downloading all sorts of things and i could not stop it, i tried everything but it just locked me out even CTRL/ALT/DELETE so in the end i had to pull out the power supply.

when i restarted i could not connect to my router again i tried every thing including spending 1h 30min with a techno from my ISP no matter what we tried it would not connect the IP address had been changed and no matter how we tried we could not change it back each time we altered it as soon as it connected it changed itself back so in the end i gave up in desperation thanked the techno for his help and used the recovery disc.

i was not able to use System Restore because some how it wiped all restore points.

anyway i have now got back on line and all is good i have all my programmes on a backup hard disk so not too harm done just time wasted.

has anybody seen anything like this before???????