XP Pro repair

Lightweight techie here!
ONLY since downloading Windows 7 beta AND IE8 with XP Pro SP3, all internet and mail is slower than previously. Also specifically cannot view Google Earth-error message 800272efe shows. NOT a firewall/anti spam or anti virus issue. Radio link at 1 Mbps used.
Repair solution offerd by official MS site is too long, complicated and risky for me to attempt.
Any free quick fix solutions available?? Help/guidance would be welcome.