Having files on your hard drive should not cause your computer to slow down. File fragmentation can make your file access time a little longer, but does not affect your operating system speed.

I would recommend the purchase of an external hard drive (or two) for backups. See the thread on this forum What if you lost your digital images? . A 2 TB drive can be bought for less than $100 US, which I feel is cheap insurance against my main hard drive failing.

Backing up the files to CD, DVD or Blu Ray is not a bad idea.

Phil