I almost did once. My computer doesn't have a big hard drive, so for me, it was very easy. Anyways, my computer came with 40 GB (36 GB after all the preinstalled programs) I installed too much, and with a year I was able to make that 36 GB into 6 GB. I was shocked to see this. I deleted some of the programs, but knowing me (forgetting to backup), my hard drive crashed and I had to reformat, losing all of my precious data. Luckily, I had one of those cool HP System Recovery Discs, and my computer was up and running again.