I have been using Photoshop CS4 for about 6 or 7 years now without (m)any issues.
However upon starting the program today. It is so slow even navigating the menus has a 2-3 second delay. It's become completely unusable simply on starting up.
The things I've tried so far are,
Running as admin
Deleting preference file
Updating Graphics drivers for Nvidia
Disabling openGL in photoshop
Increasing allowed memory
Changing and allowing of 3 possible scratch disks
All with absolutely no change.
The only thing I did between uses of photoshop that I can think of is installing Far cry 5 on a completely seperate drive from Photoshop so I don't see how that could be related.
My resource monitor shows 0.00 % used on Photoshop with no document open.
Barely any memory used (120 MB) yet it's still slow as molasses.
Adobe Photoshop Version: 11.0 (11.0x20080919 [20080919.r.488 2008/09/19:02:00:00 cutoff; r branch]) X64
Operating System: Windows NT
Version: 6.1 Service Pack 1
System architecture: Intel CPU Family:6, Model:10, Stepping:9 with MMX, SSE Integer, SSE FP, SSE2
Physical processor count: 2
Logical processor count: 8
Processor speed: 3569 MHz
Video Card: NVIDIA GeForce GTX 1080 Ti
Video Mode: 1920 x 1200 x 4294967296 colors
Video Card Driver: nvd3dumx.dll,nvwgf2umx.dll,nvwgf2umx.dll,nvd3dum,nvwgf2um,nvwgf2um
Driver Version: 126.96.36.19935
Built-in memory: 16327 MB
Free memory: 10083 MB
Memory available to Photoshop: 14603 MB
Memory used by Photoshop: 70 %
Image cache levels: 4
Application folder: C:\Program Files\Adobe\Adobe Photoshop CS4 (64 Bit)\
Temporary file path: C:\Users\Borg\AppData\Local\Temp\
Photoshop scratch has async I/O enabled
E:\, 3,64T, 3,27T free
D:\, 1,82T, 617,3G free
C:\, 238,5G, 54,3G free
Primary Plug-ins folder: C:\Program Files\Adobe\Adobe Photoshop CS4 (64 Bit)\Plug-ins\
Additional Plug-ins folder: not set
If CS4 worked without issue in the past what has changed on your system in the past few days? What version of Windows are you running. I do not thinks its windows NT like CS4 shows. If its Windows 7 see is there is a system restore point you can restore to a point where CS4 was working well.
Have you checked if some process in memory is consuming CPU (virus or other)? The PC is slow using Photoshop only?
The latest windows update service pack apparantly ran overnight while my monitor was off and basically bricked it. After system restore all is good for now until Windows wants to update the service packs again... Odd.