Ksplice is the closest alternative to a Windows Update. Since Linux kernel bugs are being fixed every now and then, it is imperative that you install Ksplice (it’s free for Ubuntu and Fedora). And since Linux Mint is a derivative of Ubuntu, you need to fix the APT line under Software Sources.
To do that, follow this procedure:
1. Open Software Sources
2. Click the Other Software tab
3. Look for these 2 entries
http://www.ksplice.com/apt isadora ksplice
http://www.ksplice.com/apt isadora ksplice (Source Code)
4. For each entry, click the Edit… button. Under Distribution, enter your Ubuntu version in lowercase (lucid in this case). Then click OK
5. Click Close, then Reload
Note: This procedure applies to Linux Mint 9 Isadora. For other versions, enter your distribution name accordingly.