I have looked at the Toshiba website they have a more than one L300 models so you would have to go their website to look here is a LINK
to their support page(click the Product Support link to find your model) and they do have documentation to help out...(which is nice)
The decision it is up to you. I own an HP laptop had Vista Home on it and did a Clean Install to Windows 7 Pro the Full version. and I really like it. If you do decide to go to Windows 7 make sure you made/have the Recovery Disk(s) to go back to Vista in the event it does not work.
Hope this Helps..and Happy Holidays