Hi, I purchase a Mac Air when they first came out and have 4 GB Ram and 64 GB Flash SSD HD. I would like to know whether I can purchase the 256 GB Flash SSD and upgrade my harddrive capacity.

use Defraggler
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I love ssd cards they are very very fast.

Replace its battery and check.

Remove the SSD and put a additional new SSD with Max capacity else use external storage

Depending upon your usage avoid using laptop while the laptop in charging mode it will decrease the battery life

Not really enough information. Does it attempt to load? Are there any messages shown on screen? You need to establish whether it's a software or hardware problem. Assuming there's an error message of some sort, what happens if you put the Windows installation disc in and boot up (having changed the Bios setting to boot from disc before the hard drive)? It should ask if you want to install Windows. If it does, then proceed and follow the links to 'repair'.

Insufficient information. Restore system, or the entire OS?

problem kya aa rhi hai

Sounds as if you have filled up all your available RAM You might try increasing your page filing however that will slow you down a bunch. Best solution is what I have a SSD with the OS and PROGRAMS on it with a TB HDD for storage extra page filing with an SSD is just as fast maybe faster than the straight memory. A 64 GB SSD will hold Windows 7 Ultimate, MS Office 2007 Enterprise, And Adobe CS$ design Premium With about 25 GB left over. 8 GB Ram Quad core With SSD page filing MS recommended 12 GB so I now have essentially 20 GB of RAM and 40 GB SSD OS and Programs and the TB original Drive makes great storage You do not have enough table space (usable fast memory /disk) for all you are opening that is why some thing must close or stop