For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
Outlook Google Calendar Sync - Offers calendar synchronisation between Outlook and Google, including attendees and reminders.
Dropbox - Online Sync and File Sharing
GO Contact Sync Mod - GO Contact Sync Mod is an open source tool to synchronize your Microsoft Outlook contacts with...
Google Drive - Access and sync your files anywhere
gSyncit - gSyncit Outlook Cloud Synchronizer. Outlook Calendar, Contact, Task, Note Synchronizer supporting Google, Toodledo, Evernote, Informant, iCloud, AOL, Yahoo, Synology, Fruux, Memotoo and CalDav/CardDav services.
Mega - Secure File Storage and collaboration