they will always be a bit behind as hardware moves on quicker that the books but the overriding principal is the same.
The main differences moving forward will the the OS but for repairing PC's this is less important really. To be 100% honest the best knowledge comes from experience and so much you learn from experience will never be covered in any books.
If you found the PC Repair 21st Edition too in depth and had too much reminiscing (which it does) then the PC Repair for Dummies is probably a good read as it wont go in to historical ramblings about the CPU wars etc.
The main differences moving forward will the the OS but for repairing PC's this is less important really. To be 100% honest the best knowledge comes from experience and so much you learn from experience will never be covered in any books.
If you found the PC Repair 21st Edition too in depth and had too much reminiscing (which it does) then the PC Repair for Dummies is probably a good read as it wont go in to historical ramblings about the CPU wars etc.