I purchased a Hard drive online from Dell, the hard drive appeared on the page that searched for compatable HDD for my particular service tag number. I received the HDD and when I tred to install it my computer would not recognize the HDD. On 6-1-08 I contacted an online tech who instructed me to reinstall and then run a test which was quite long. He said he would call back the next morning at 5 am but he did not. On 6-11-08 I submitted a return tequest from Dell and I received an automatic confirmation. They say they have no record of that. On 6-12-08 I reached 21 days. Now they will not do an exchange because I'm past the 21 days and will not acknowledge the return request I sent in before the 21 days.