My son has the same Netbook and I noticed it was ababysmally slow after he started using it. Not that one should expect blinding speeds out of an Atom processor.
here are some things you can do to help speed things up.
1. more RAM. Buy more memory. Max it out if you can
2. Defrag. Defrag the hard drive. From my own experience, Windows computers all come highly fragmented straight out of the box. Once you defrag the hard drive, schedule the software to do it automagically once per week.
3. McAfee will definitely slow you down. There are other solutions which aren't as intrusive.
4. Re-index the Registry. CCleaner will do that for you and it's free. Download it, install it and run it. Regularly.