HDDScan report after read-test:

<5ms 201203
<10ms 103325
<20ms 1100
<50ms 6
<150ms 0
<500ms 1 (first sector on disc)
>500ms 0
Bads 0

My friend returned this laptop to me after me having done a low level format (which removed some bad sectors), because he says his clean installed windows xp was running really slow. Can this have anything to do with it and if so, is it worth trying to mark the slow sectors as bad with MHDD or should I just replace his laptop's hard disk?

You can try marking it as a bad sector as see what happens.
If it will disappear, you good to use this drive for another 3-12 month

_________________
www.datarecoveryne.com