Windows has many "special folders" like "My Computer" and "Recycle Bin" that are not part of the normal folder system you can specify with a "path" on an action in Rainmeter, or launch differently then they appear in Explorer.
Windows Shell: commands
These folders can be accessed by using the Windows Shell: command and the CLSID identifier codes that Windows assigns to these folders in the Windows Registry. If you know the codes, you can launch these with ease.
Add Network Location ::{D4480A50-BA28-11d1-8E75-00C04FA31A86} Administrative Tools ::{D20EA4E1-3957-11d2-A40B-0C5020524153} Applications ::{4234d49b-0245-4df3-b780-3893943456e1} AutoPlay ::{9C60DE1E-E5FC-40f4-A487-460851A8D915} BitLocker Drive Encryption ::{D9EF8727-CAC2-4e60-809E-86F80A666C91} Bluetooth Devices ::{28803F59-3A75-4058-995F-4EE5503B023C} Color Management ::{B2C761C6-29BC-4f19-9251-E6195265BAF1} Command Folder ::{437ff9c0-a07f-4fa0-af80-84b6c6440a16} Common Places FS Folder ::{d34a6ca6-62c2-4c34-8a7c-14709c1ad938} Control Panel ::{5399E694-6CE5-4D6C-8FCE-1D8870FDCBA0} Control Panel (All Tasks) ::{ED7BA470-8E54-465E-825C-99712043E01C} Control Panel (always Category view) ::{26EE0668-A00A-44D7-9371-BEB064C98683} Control Panel (always Icons view) ::{21EC2020-3AEA-1069-A2DD-08002B30309D} Credential Manager ::{1206F5F1-0569-412C-8FEC-3204630DFB70} Date and Time ::{E2E7934B-DCE5-43C4-9576-7FE4F75E7480} Default Programs ::{17cd9488-1228-4b2f-88ce-4298e93e0966} delegate folder that appears in Computer ::{b155bdf8-02f0-451e-9a26-ae317cfd7779} Desktop (folder) ::{B4BFCC3A-DB2C-424C-B029-7FE99A87C641} Device Manager ::{74246bfc-4c96-11d0-abef-0020af6b0b7a} Devices and Printers ::{A8A91A66-3A7D-4424-8D24-04E180695C7A} Display ::{C555438B-3C23-4769-A71F-B6D3D9B6053A} Documents (folder) ::{A8CDFF1C-4878-43be-B5FD-F8091C1C60D0} Downloads (folder) ::{374DE290-123F-4565-9164-39C4925E467B} Ease of Access Center ::{D555645E-D4F8-4c29-A827-D93C859C4F2A} E-mail (default e-mail program) ::{2559a1f5-21d7-11d4-bdaf-00c04f60b9f0} Family Safety ::{96AE8D84-A250-4520-95A5-A47A7E3C548B} Favorites ::{323CA680-C24D-4099-B94D-446DD2D7249E} File Explorer Options ::{6DFD7C5C-2451-11d3-A299-00C04F8EF6AF} File History ::{F6B6E965-E9B2-444B-9286-10C9152EDBC5} Font Settings ::{93412589-74D4-4E4E-AD0E-E0CB621440FD} Fonts (folder) ::{BD84B380-8CA2-1069-AB1D-08000948F534} Frequent folders ::{3936E9E4-D92C-4EEE-A85A-BC16D5EA0819} Games Explorer ::{ED228FDF-9EA8-4870-83b1-96b02CFE0D52} Get Programs ::{15eae92e-f17a-4431-9f28-805e482dafd4} Help and Support ::{2559a1f1-21d7-11d4-bdaf-00c04f60b9f0} HomeGroup (settings) ::{67CA7650-96E6-4FDD-BB43-A8E774F73A57} HomeGroup (users) ::{B4FB3F98-C1EA-428d-A78A-D1F5659CBA93} Hyper-V Remote File Browsing ::{0907616E-F5E6-48D8-9D61-A91C3D28106D} Indexing Options ::{87D66A43-7B11-4A28-9811-C86EE395ACF7} Infared (if installed) ::{A0275511-0E86-4ECA-97C2-ECD8F1221D08} Installed Updates ::{d450a8a1-9568-45c7-9c0e-b4f9fb4537bd} Internet Options (Internet Explorer) ::{A3DD4F92-658A-410F-84FD-6FBBBEF2FFFE} Keyboard Properties ::{725BE8F7-668E-4C7B-8F90-46BDB0936430} Language settings ::{BF782CC9-5A52-4A17-806C-2A894FFEEAC5} Libraries ::{031E4825-7B94-4dc3-B131-E946B44C8DD5} Location Information (Phone and Modem) ::{40419485-C444-4567-851A-2DD7BFA1684D} Location Settings ::{E9950154-C418-419e-A90A-20C5287AE24B} Media Servers ::{289AF617-1CC3-42A6-926C-E6A863F0E3BA} Mouse Properties ::{6C8EEC18-8D75-41B2-A177-8831D59D2D50} Music (folder) ::{1CF1260C-4DD0-4ebb-811F-33C572699FDE} My Documents ::{450D8FBA-AD25-11D0-98A8-0800361B1103} Network ::{F02C1A0D-BE21-4350-88B0-7367FC96EF3C} Network and Sharing Center ::{8E908FC9-BECC-40f6-915B-F4CA0E70D03D} Network Connections (in PC settings) ::{38A98528-6CBF-4CA9-8DC0-B1E1D10F7B1B} Network Connections ::{7007ACC7-3202-11D1-AAD2-00805FC1270E} OR ::{992CFFA0-F557-101A-88EC-00DD010CCC48} Network (WorkGroup) ::{208D2C60-3AEA-1069-A2D7-08002B30309D} Notification Area Icons ::{05d7b0f4-2121-4eff-bf6b-ed3f69b894d9} NVIDIA Control Panel (if installed) ::{0bbca823-e77d-419e-9a44-5adec2c8eeb0} Offline Files Folder ::{AFDB1F70-2A4C-11d2-9039-00C04F8EEB3E} OneDrive ::{018D5C66-4533-4307-9B53-224DE2ED1FE6} Pen and Touch ::{F82DF8F7-8B9F-442E-A48C-818EA735FF9B} Personalization ::{ED834ED6-4B5A-4bfe-8F11-A626DCB6A921} Pictures (folder) ::{3ADD1653-EB32-4cb0-BBD7-DFA0ABB5ACCA} Portable Devices ::{35786D3C-B075-49b9-88DD-029876E11C01} Power Options ::{025A5937-A6BE-4686-A844-36FE4BEC8B6D} Previous Versions Results Folder ::{f8c2ab3b-17bc-41da-9758-339d7dbf2d88} printhood delegate folder ::{ed50fc29-b964-48a9-afb3-15ebb9b97f36} Printers ::{2227A280-3AEA-1069-A2DE-08002B30309D} OR ::{863aa9fd-42df-457b-8e4d-0de1b8015c60} Programs and Features ::{7b81be6a-ce2b-4676-a29e-eb907a5126c5} Public (folder) ::{4336a54d-038b-4685-ab02-99bb52d3fb8b} Quick access ::{679f85cb-0220-4080-b29b-5540cc05aab6} Recent places ::{22877a6d-37a1-461a-91b0-dbda5aaebc99} Recovery ::{9FE63AFD-59CF-4419-9775-ABCC3849F861} Recycle Bin ::{645FF040-5081-101B-9F08-00AA002F954E} Region and Language ::{62D8ED13-C9D0-4CE8-A914-47DD628FB1B0} RemoteApp and Desktop Connections ::{241D7C96-F8BF-4F85-B01F-E2B043341A4B} Remote Printers ::{863aa9fd-42df-457b-8e4d-0de1b8015c60} Removable Storage Devices ::{a6482830-08eb-41e2-84c1-73920c2badb9} Results Folder ::{2965e715-eb66-4719-b53f-1672673bbefa} Run ::{2559a1f3-21d7-11d4-bdaf-00c04f60b9f0} Search ::{9343812e-1c37-4a49-a12e-4b2d810d956b} Search Everywhere (modern) ::{2559a1f8-21d7-11d4-bdaf-00c04f60b9f0} Search Files (modern) ::{2559a1f0-21d7-11d4-bdaf-00c04f60b9f0} Security and Maintenance ::{BB64F8A7-BEE7-4E1A-AB8D-7D8273F7FDB6} Set Program Access and Computer Defaults ::{2559a1f7-21d7-11d4-bdaf-00c04f60b9f0} Show Desktop ::{3080F90D-D7AD-11D9-BD98-0000947B0257} Sound ::{F2DDFC82-8F12-4CDD-B7DC-D4FE1425AA4D} Speech Recognition ::{58E3C745-D971-4081-9034-86E34B30836A} Storage Spaces ::{F942C606-0914-47AB-BE56-1321B8035096} Sync Center ::{9C73F5E5-7AE7-4E32-A8E8-8D23B85255BF} Sync Setup Folder ::{2E9E59C0-B437-4981-A647-9C34B9B90891} System ::{BB06C0E4-D293-4f75-8A90-CB05B6477EEE} System Icons ::{05d7b0f4-2121-4eff-bf6b-ed3f69b894d9} Tablet PC Settings ::{80F3F1D5-FECA-45F3-BC32-752C152E456E} Taskbar and Navigation properties ::{0DF44EAA-FF21-4412-828E-260A8728E7F1} Text to Speech ::{D17D1D6D-CC3F-4815-8FE3-607E7D5D10B3} This PC ::{20D04FE0-3AEA-1069-A2D8-08002B30309D} Troubleshooting ::{C58C4893-3BE0-4B45-ABB5-A63E4B8C8651} User Accounts ::{60632754-c523-4b62-b45c-4172da012619} User Accounts (netplwiz) ::{7A9D77BD-5403-11d2-8785-2E0420524153} User Pinned ::{1f3427c8-5c10-4210-aa03-2ee45287d668} %UserProfile% ::{59031a47-3f72-44a7-89c5-5595fe6b30ee} Videos (folder) ::{A0953C92-50DC-43bf-BE83-3742FED03C9C} Web browser (default) ::{871C5380-42A0-1069-A2EA-08002B30309D} Windows Defender ::{D8559EB9-20C0-410E-BEDA-7ED416AECC2A} Windows Mobility Center ::{5ea4f148-308c-46d7-98a9-49041b1dd468} Windows Features ::{67718415-c450-4f3c-bf8a-b487642dc39b} Windows Firewall ::{4026492F-2F69-46B8-B9BF-5654FC07E423} Windows To Go ::{8E0C279D-0BD1-43C3-9EBD-31C3DC5B8A77} Windows Update ::{36eef7db-88ad-4e81-ad49-0e313f0c35f8} Work Folders ::{ECDB0924-4208-451E-8EE0-373C0956DE16}
Note: These commands exist only from Windows 8 onwards.
Since Windows 8, Microsoft introduced a new software enviourment known as UWP (formerly known as Metro-style apps). These can be run using the Shell:AppsFolder command, along with special parameters.
The command should take the form of Shell:AppsFolder\FolderName!ShortCutName.
The necesary info for lunching an app are:
The Folder name
Found by opening the "C:\Users\YourName\AppData\Local\Packages" folder
The Shortcut name
Found by opening the Shell:AppsFolder folder (to get there, put that path into Windows Run), creating a Desktop shortcut of the app you want and inspecting its proprieties.
Note: The majority of the time, the Shortcut name will be App, there are exceptions however, like for the Calendar app.
So, to get the necesary info you will have to:
Open the folder "C:\Users\YourName\AppData\Local\Packages"
Find the application you want, and copy that "folder"'s name.
Inside the folder, copy the name of the "shortcut" (usually "App" with applications included with Windows)
Put the two on a shell command of Shell:AppsFolder\FolderName!ShortCutName
An example for the Camera app would be:
The folder name is "Microsoft.WindowsCamera_8wekyb3d8bbwe"