Second hard drive not seen in Windows 7, but see it just fine in linux

does it show up in Device Manager under Disks drives?

what about diskpart?
type 'diskpart' in the start menu.
then in the cmd windows that opens type 'list disk'.

Only see my boot drive in device manager and diskpart, do not see the secondary drive in either. Also, it was working when I left for work this morning, got home and computer had gone to sleep, when I woke it up, secondary drive was missing, restarted computer, drive was back, then went away like 20 minutes later, restarted again, drive was back, then went away after 10 minutes, checked drive connections, turned it back on and it's been gone ever since, but can still see it and interact with it with no problems in linux

Also just checked and from what I can tell it isn't showing up in BIOS. How can that be if I can still see it and use it in Linux?

Just a guess, but seeing that the problem started after Windows went to sleep, you might try this: Win7 Control Panel - System & Security - Power Settings - Edit Power Plan - Advanced Power Settings... Under "Hard Drive" you can change the option to "Never" turn off the hard drive for power saving. Don't know if it will fix your problem.

I see your point there, that may have been the reason it turned off originally possibly, but still acting the same after changing the settings.

Here's another guess. In Mint, open gparted and make sure the main hard drive is the only drive with the boot flag turned on.

If the boot flag is turned on for both drives, then probably Mint installed its Grub boot loader onto the second drive. If you turn off the flag on the second drive, you might not be able to boot into either system... in which case you'd need to use the BIOS boot menu to boot the second drive so you could have access again to Grub. So its probably best to first just see if both drives have the boot flag activated or not.

EDIT: Some of the above could be incorrect.

Did that, secondary drive not flagged as boot, but there is a partition on it that is flagged as "msftres"

Does the partition labeled "msftres" have a boot flag? If so, does the Windows partition on the first drive also have a boot flag? Is there also a "msftres" partition on the first drive?

No boot flag that I can see on the secondary HDD at all, not on the msftres partition or otherwise. On the main HDD, there is a boot flag on the windows partition, and no msftres flags on that HDD at all

I'm at a loss for any more guesses. Strange that it worked for a while then stopped. If I can come up with any new ideas, I'll be back tomorrow. Hopefully, before then, someone will come along with more experience in these issues.

Its normal.reason if u r install both os in single hdd and make dual boot the problem will raise because files colapse and windows and linux use different partition methods.hdd max speed is for 500gb 7200rpm is 65mb per sec.if u open many programs in windows and linux ram also confused and hdd also confused by virtual ram option.

solution: for normal users:Use separate partition for windows and linux.make sure the partition for linux has no files in that.install linux mint under windows. so now see linux in windows add or remove programs.if any problem in linux u r not known to cure that simply uninstall it.dont use many programs at a time same problem can raise.
for gamers or want multitasking: install linux in another hdd under windows. the problem dont raise.
change power option to best performance.increase ram.

Reason for disk work in linux not in windows. because linux uses light application for browse files but windows has internetexplorer its the difference. This is the main reason and many people give advice for backup data from repair hdd" try it with linux cds".

but if the bios cant even see it how does linux see it?