Slow on copying and extracting file

Hi, when I 'drag and drop' files from 1 hardrive to the other, I find it incredibly slow and also lags my system. That goes the same with norton antivirus scanning my computer and also extracting files.

Does RAID help solve this problem or do I need better programs for copying and extractin'?

has this happened before or is it just recently?

It always happen
it takes an hour to copy files of 20GB from one HDD to another (quantum 20GB 7200 2M to WD800JB) by drag and drop when they are in the same channel (Primary slave and master)

Then my computer begins to act like a 32MB with Pentium 2 PC when the CPU and memory is not even half-used

Each IDE channel can only handle one instruction at any given time, so copying files from one partition to another, or from master to slave on the same channel, takes about twice as long as copying from the primary to the secondary channel and vice versa.

Also make sure DMA is enabled.