I am confused to upgrade a new hard disk in my computer. I am currently using 160 GB hard drive with 2gigs of RAM and Windows Vista. I had added one more 320Gb hard drive which failed within some time. It is still lying for replacement. I need some simple tips to check out first before buying a better hard disk for a computer. My system is used for regular backups and it is necessary for me to get a reliable solutions. Thanks in advance.