Thanks for all your help. I've checked my fragmentation level and it's ok. Installed the latest graphics driver, uninstalled some plugins that I haven't used in ages. So far everything seems to be OK. Just have to put it down to "one of those things".

I think it must be something like that. My graphics driver is up to date. I'll just have to monitor the situation and keep trying stuff if it crops up again.

My wife's PC has very similar hardware to mine and she is running Photoshop without any problems. She has an ATI Radeon HD 5670 card but is using the up to date driver, version 8.892.0.0, Catalyst Version 11.9.

One thing I did notice that was different was that her Catalyst Control Centre shows her Maximum Bus Setting PCI Express 2.0 x16 whereas mine showed X8, yet the card is fitted to the X16 slot..

I did install a USB 3.0 PCIe card in the other PCI Express X8 slot early last week. It was the only other slot on my motherboard (Gigabyte GA-P55-UD4) that was PCIe 2.0. I've just removed that card and my Maximum Bus Setting PCI Express 2.0 is now X16.

Whether that is the root of the problem I don't know, but will see how things go today. So I've left my graphics driver unchanged at this time; otherwise we won't know which change made the difference (if any).

As I understand it after a little research if you plug a card into the X8 slot it splits the bandwidth between that and the X16 slot. So the X16 is reduced to X8. Beyond that my knowledge ends.

Adding the USB 3.0 card was the only change I could remember making immediately prior to encountering this issue with Photoshop.

The only other thing was that I was using Nik Silver Efex 2.0 and a couple of times I got the sequence wrong and tried to save before applying which did freeeze both Photoshop and Bridge. But my subsequent removal and re-install of Photoshop and plugins would surely have corrected any damage that may have caused. I did make sure that all Photoshop and Adobe products were completely removed from my system before re-installing.

Sorry about the lack of response, but I decided to take drastic action. I re-installed Windows and all my Adobe products. Everything (Windows, Photoshop, Graphics driver) is updated, activated and it hasn't solved anything!

After 1st boot of the day everything works in Photoshop. I can close it and re-open it and it works. Then if I close it and do something else for a couple of hours or so I can open Photoshop but it refuses to display any images, they still show in Open Recent even though they didn't show on the screen. Along with no images displaying, if I click on Color Settings under Edit nothing happens, so the two issues are linked. It happens at the same time in the same way in both 64bit and 32bit Photoshop.

I've tried with OpenGL on and off, tinkered with Preferences, used old graphics drivers and the latest.

I have discovered that I don't need to re-boot the machine, just log out and log back in again and everything's fine. But there doesn't seem to be anything I do, not do, that I can think of, replicate, that causes the issue. It seems to happen when it happens after a non specific period of time of Photoshop being closed. There has to be something causing it, but I've run out of ideas.

My wife has not encountered any issues, she has nearly identical hardware/software (her graphics card is an ATI HD 5600 series, mine is a 5700). Otherwise everything else is the same, and the same plugins in Photoshop. The only difference is she has version 12.04 and I am using 12.1.

I'm now at a complete loss as to what to do apart from downgrading to 12.04.

I'm not experiencing any other issues with any other hardware/software.

Hi again Noel

I calibrate the monitor using a Datacolor Spyder3 unit. It loads the calibrated profile into the graphics card at system start. I will try using another profile but I've been using the Datacolor profile for a long time. Well before this particular issue came along to haunt me.

My AV is Norton Internet Security, though when this problem appeared I was using Microsoft Security Essentials

At this time I haven't any 3rd party plugins installed, as I am trying Photoshop without to try and rule out plugins. I have Nik complete Collection which along with Knoll Light Light Factory 3.5 would be my only 3rd party plugins. I also have a mass of brushes that I am not even going to try and list, but they're not in the Presets at this time. I'm trying to use as vanilla an install as I can to try and elminate outside influences.

I have the settings in Photoshop set to default, apart from changing the scratch disks to two internal drives (D: & E:) not C:, my units are set to inches and I have Prophoto set as the default colour space with the options set to ask, but that's it. It's never been any different since I started using Photoshop years ago.

I also have Adobe Illustrator, Indesign and Dreamweaver installed along with Acrobat X.

My Win 7 install is pretty much vanilla. I have set a Copy To and Move To option that I use in the Explorer context menu. I don't use the Aero desktop, just Win 7 basic. I have MS Office 2010 Professional, Corel Painter 12, Cyberlink PowerDVD 10, Ashampoo Burning Studio 10, Dynamic Auto Painter(for fun), Shark 007 multimedia codecs, STALKER Call of Pripyat, HP/ Epson printer drivers only, Epson Scan, 7zip 64bit, CCleaner, and that is it.

I use IE9, not an add on browser and when I fancy some music I use WMP 12.