Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A Freezer

I work for the Gov't (NASA). We purchased this computer in July of 2005. Since then, it has frozen roughly 25-30 times. The person who writes that OS X doesn't freeze, doesn't understand Operating systems. Any OS can freeze/crash due to flaky hardware. One obvious case is that of memory. If the memory is bad, how can the OS function? True, if there's a software problem, more times than not, the OS can gracefully shut down the ill behaving application. No such luck w/ bad hardware. In my case, the last freeze has cost me 4 days of work, and a new hard drive. Apple was nice enough to send out new memory chips (the suspected culprit), though neither of us are certain this is indeed the case. The freeze happens randomly.My warning to all who own this machine. Do backups...