Power windows stop working. Happened two weeks ago and i replaced the fuse and it worked fine for another week. After the fuse blew out again i replaced it and it keeps blowing out.

you have a short or grounded out wire. that is why they keep blowing. trace your wires and check for damage, also you can use a voltmeter.

if i do find a damaged wire do i have to replace the whole wire or is there a way to repair it

just cut out the bad area and use another piece of wire, trim back about a half inch of the insulation, and connect each end with but connectors or electrical tape