Floppy disks, especially, must be treated properly if you want to avoid problems with them. Check out this media care section for much more information. If you set up the system properly, you can actually have Windows 95 turn off the power to an ATX PC when you tell it to shut down. Here are a few of quick tips. First, look through the disk for temporary files or items you aren't using any more, and delete them if you are sure they are unneeded.
Most disks have at least a few megabytes that that can go.
Third, periodically empty out your Web browser's temporary cache file. I've seen over 100 MB of space recovered on many systems through a combination of these three. There are two primary interfaces used for mice on modern PCs. This is fine and many systems will support either type. Because the two types of mice use different electrical signalling.