Microsoft Outlook - (i have already done an article for this check)

• em Client (emClinet)
  - looks almost identical to microsoft outlook
  - It has a calender built in
  - it is limited to one email account though on the free version
  - Importing from outlook is very easy (simple wizard)
• Thunderbird
  - no inbuilt calendar, but you can add one on and import outlook calendar events
  - you can import from outlook
  - signatures is a bit flaky
  - completely free and updated often

These are some articles on other Outlook alternative

• 3 Best Free Alternatives To Microsoft Outlook
• FreeOutlookAlternatives.com - Helping you choose the best e-mail client

Microsoft Office

• Libre Office
• Open Office

Security Software

• Microsoft Security Essentials
• Comodo Firewall (you can either have antivirus or firewall installed not both)
• Comodo Antivirus
• Comodo Antispam (basic, uses local lists and passcodes only)
• Comodo Backup
• Rapport - get this from your bank (or natwest)
   
• AVG
• Panada Antivirus
• Avast

Other Softwares

• peazip - unzipping and zipping - it does everything
• xampp - local webserver
• RSSOwl
• RSS Bandit
• filezilla
• KeePass and last Pass - password amangers - check which is best