Recently, almost every file I try to copy into my HDDs gets corrupted. When writing to the disk, some portion of the file is replaced by random bytes (Checked using Diff apps) There's no problem reading existing files. I'm pretty sure it's not the HDD, becasue I've tried another HDD (a brand new 1TB WD) and the problem still remains. I have an AMD Athlon 64 X2 CPU, an ASUS M2NE motherboard, 2 WD SATA II HDDs (320GB + 1TB) and 3GB of Corsair RAM. My OS is Windows 7 (64 bit) Now, what could be the cause of this? If it's the motherboard, can it be fixed by using a PCI SATA card?