The most major of which are capacity and speed. You may could refer the  specification by SD Association (www.sdcard.org)

We do not suggest PNY flash card as bootable of Windows system or some device that can run an OS from.
Reminders, PNY is not responsible for any damage or failure of any third party equipment that used with PNY products.

We don't provide data recovery service. We suggest you try to found some free or trial version of the data recover software on the internet, or to contact the company that are specializes in the data recovery service.

For the SD card, there is a lock switch on the left side of the card. You can push up the switch to unlock it. If the lock switch looses or can be moved easily, then fasten it. If can't solved, or the card doesn't have any lock switch, we suggest you contact the original store / retailer for warranty service.
Note: product warranty service that not include data recovery service. PNY is NOT liable for data loss in connection with the product, regardless of the cause.

We suggest you confirm the two parts the follows,

1. Mark sure your device power supply.
2. Make sure the card's file system, capacity and speed are compatible with your device.

For all cards, we suggest you often back up files of the card, And notice two parts the following:

1. Be sure to avoid removing them from devices while data is being accessed on them, i.e., pulling it out of a camera while you are previewing an image.
2. Do not leave them in devices with low batteries. If the batteries die while the card is in the unit, cards may be corrupted by the sudden power loss.