I'm considering buying an external hard drive. My internal HD is 160GB, should i buy a 160GB EHD or something bigger, such as a 250GB? It's going to be used as a backup to the Main HD, so i want to be able to put everything on it, i will need, when i have a System Crash.

it depends , is your current hard drive full?
what do you keep on it?

if you have an opportunity to buy a larger ext drive, buy it.

According to Defrag, C is 93% free space. I guess i should rephrase my question. Is a 160GB External Hard Drive big enough to store ALL the files from my present Internal HD and all i will add in the future? If anybodies interested, Walmart has a SeaGate 160GB External HD for $114.00 and a 250GB for $149.00. SeaGate is the brand that my puter has now. I had to change it 1 month after i purchased the computer, because, HP said it got infected by a Virus. I didn't know a Virus could leave signs of over-heating. HP con(vinced) my wife into buying Norton Internet Security 2006. Do i need to add how much i hate Norton IS 2006?

As mentioned before, buy the biggest capacity drive you can afford at the moment. Prices are crashing on a daily basis and it definitely makes sense to invest in a large capacity drive. If I was in your place, I'd go for a minimum 250 GB HD, as it's fairly future proof, and with Vista around the corner. Vista, after a fresh install occupies ~8.5 GB disk space.

Sounds like good advise to me. Now i just need to convince the wife to go the extra $40.