In all likelihood the issue is tactics. Computers are extemely adept at tactics, at least out to 2-3 moves even on the lower levels, so you need to get very familiar with typical tactical shots like knight forks, pins, and hanging pieces. I've found that knowing openings is also of high importance when playing a computer: there are so many opening traps and tactics based on simple opening mistakes that it takes at least dozens of games to start to learn the generalities of what to do and what not to do. Also, computers use a book of opening moves, which gives them an additional advantage, so in a sense they're cheating, so if you want to "cheat" back (not against the rules when playing a computer here!), you can refer to some book of opening moves.
More tips: (1) Computers at a low level are very susceptible to positional problems regarding gambits because they value material far above position. They can't resist a gambit, then they try to hang onto the extra material until their position is destroyed. (2) Computers at a low level are very poor at endgames since they are using lookahead rather than general logic and common sense, so if you can reach the endgame you can probably win.
http://www.chess.com/forum/view/general/chesscom-computer-level-10
BACKGROUND: I have been playing chess for 6 months now. So far, I have only gone through Bobby Fischer Teaches Chess, and a few games of Logical Chess by Irving Chernev. I have played ~300 legit live games and have a rating of ~1100.
I just cannot seem to beat the computer on a 1000 rating no matter how hard I try. I can easily beat the computer on a 800 rating, but when I play on 1000 rating, I always lose.
Is there a different strategy to use when playing a computer?
Any tips?