My computer is running very slow. System idle is almost always 98-99% and only half the memory is employed. I utilize disk cleanup, cleaned up startup programs, defragmented the HDDs, increased the virtual memory to over 4 Gb per HDD, and did thorough virus and spyware scan. I don't use the system for gaming or other taxing programs. It is especially slow when transfering files between HDDs.
ASRock A780LM motherboard
AMD Athlon 64 X2 6400+ (dual-core, 3.2 GHz)
2 Gb DDR2 800 memory
primary HDD - Western Digital 250 Gb SATA
secondary HDD - Samsung 1 Tb SATA
NVIDIA GeForce 8600 GT video card
IDE DVD/CD burner
Wireless network card
Task manager typically says i use 1-5% of the CPU and about 900 MB memory when idle.
First, reduce your virtual memory space, that will just make the problem worse as it will be choosing to leave more ram open and call the HDD more often. Im willing to bet that the source of your issue is that your primary HDD is pretty slow by todays standards, a slow HDD is actually the biggest source of the system seeming sluggish and running slowly, since its "especially slow when transfering files between HDDs" that implies to me that your slowest part is HDD related.
I never had problems with this drive before. It seems it is actually the secondary drive that is causing the problems. I use it to store media files. It's half full. When I explore the drive, it frequently becomes non responsive.