You may need to repair guid partition scheme sometimes. As a matter of fact GUID partition table is used in Intel based Mac. This table lets you to boot drive easily, but in some point of time damaged occurs in this partition table due to several reasons including incompatible drive, volume header corruption and other related issue. As result your Mac shows weird behavior which include abrupt freeze, crash etc. That's why one must repair guid partition scheme as early as possible. By the way disk utility can be used for resolving minor issue associated with volume else reformatting hard drive is the mere option. In case of any data loss scenario you should go with restoring of Mac data. Having copy of Mac file would be very beneficial in retrieving lost file. Otherwise Mac Data Recovery Software must taken into consideration for complete restoration of missing data. The tool has sophisticated and robust scanning mechanism through which any type of adverse situation can be tackled conveniently. The solution even contains preview feature that allows to select the desired file which you want to restore. It provides secure, intuitive and effective recovery in nice way. Thus you can repair guid partition scheme.