is the reason why i cannot receive attachments on my email address at home because my computer hasnt got enough 'bytes'? if so, how do I get more bytes please?
If you don't have enough system memory (RAM), the operating system will use the hard disc as extra memory. If you run out of disc memory then, you could buy another hard drive, or a bigger one, but that would mean having to transfer your existing files to it. These days a new computer will typically have around 256 or 512 MB of RAM and at least 80 GB hard drive. Your computer would have to be pretty old (or just crap) for the above explanation to apply.
Is it a jpeg picture you're trying to open? I sometimes get this opening jpegs in Microsoft Photo Editor which is usually the default prog for jpegs if you have Office installed. What may help is if you save the file to your hard drive ("My Documents" recommended), then click on it once with the right mouse button, slide down to "Open With...." and choose "Windows Picture & Fax Viewer" or perhaps another imaging program listed there.