You might want to google the 2 and compare them.
Since, I am in the mood to type I will break it down for you.
In a nutshell, A+ n MCP are very different in that A+ is a CompTIA vendor neutral 2 part exam that if you pass, proves to an employer that you have a foundational background in the hardware department of computers. What this means is that you have at least the 'know how' of troubleshooting any Dell, Gateway etc;...computer regardless of who manufactured it. Among a few other things a pc technician would do , like making system wide changes in the BIOS and soforth.
The A+ is where most noobs start to learn about computers and its heck of a lot easier to pass this exam.
On the flip side, MCP exams can be tough depending on which one you are taking. You can be an MCP by taking and passing any single one of the Microsoft exams. 210,270,290 etc;... Most people don't stop at MCP status and they are more than likely working towards a higher level cert like the MCSA MCSE or MCDBA. Some are following the 2000 track and others are onboard the more difficult 2003 track.
2003 exams = 20% fail rate first attempt
The MCSE 2003 server and infrastructure exams with their new testing methods that include simulations have become a bit more difficult and the exams are very much gaining back credibility in the industry. You should not take these exams thinking you can pass by simply memorizing questions b/c you will fail[/color].
Passing the 270 client operating system exam would certify you as an MCP in XP Pro and declares you an expert. This is just the beginning of the MCSE 2003 track that requires 7 exams and the MCSA which you can earn (in the middle) requires passing only 5 of the 7 total exams.
MCSE is the most popular IT certification on the planet.
The exams do a good job of measuring product knowledge of a person working in the IT field. Any microsoft exam is worth getting if you work with that product on a daily basis supporting users in a domain environment.
If not, then you will be handing over bill gates 125 bucks for nothing.