You could if you had the skill,but you'd want to use waterproof materials at least..It's really not that expensive to buy one though.
No unless your laptop has a slower processor in which case it will take longer to load on your laptop.
Basically you are going to get some fabric (preferably something like neoprene), something stiff or cushioning, cut the fabric to the dimensions of your laptop plus room for sewing, and sew it together. I found a few different instructions that you can check out to choose the one that works the best for you. These are http://www.instructables.com/id/Laptop-bag/, http://almostfrugal.com/2008/09/12/frugal-ikea-hacks-make-your-own-laptop-case/, http://www.instructables.com/id/Laptop-Sleeve-from-a-FedEx-Envelope/ and http://arstechnica.com/gadgets/news/2009/08/how-to-make-your-own-laptop-sleeve.ars.
A Laptop Case
One can possibly find a funky laptop case at an online retailer such as Amazon, or an auction site such as eBay. Another option is to take a plain laptop bag and add one's own design elements to make it match their style.
Go to the website and make a account
There are many different types of laptop cases. However, it is probably best to take your laptop to the store and make sure it fits. Your laptop will generally be heavier than your case, so you should make sure you buy a lightweight laptop of weight is an issue.
if your referring 'computer' as a laptop, then its a storage case that you put the laptop in
= To get a case for your MadDog CDDVD playerburner for laptop?" =
A 13" laptop case.
Case Logic 15.4" Canvas Laptop Messenger Bag is the best laptop case on the market for under $50
Carry the laptop in a padded case designed for the purpose.
A case from kolobags will be both stylish and protect your laptop.