The pics you uploaded were probably .bmp which is a VERY large filesize format... and usually the forum software doesn't actually show the picture itself, but a link to the picture... (which actually all the pictures in posts on the forum are "thumbnail links" to the actual picture... you can click them and up pops the box with a mini-version of it, and you can click THAT and get the full-size version on the screen, but you have to click 'back' to go back to the post again, or you can always right click "open in new tab" which is what I usually do. I actually don't care for the pop-up version most of the time).
You need to put your pics into .jpg format, which is MUCH smaller (more compression). Open your picture in your "windows photo gallery" or whatever, then at the top menu bar, click "open" and then highlight and click "paint". The picture will then open again in the "Paint" program on your computer, and you can then change the format and size of the picture as needed. To change the format, go over to "file" and click it, go down to "save as" and click that, the box will pop up with the location you're saving it to, filename (already in the box, highlighted, can be changed or added to if you want to keep the original 'as is'.) and the "save as file type". Click this and select ".jpg" from the menu... then click the 'save' button at the bottom of the popup window. The picture will now be saved as a duplicate of the original (when changing formats) in the .jpg format. Now "X" out of the pic in paint and windows gallery, and hover your cursor over the new photo icon in the pictures folder of the .jpg version you just created... it will open a little pop up box that tells you if it's the .jpg version or the .bmp version, and the FILE SIZE. If the .jpg is over about 400 KB (which is the limit on most of the forums, usually just under 400KB IIRC) then click the .jpg pic to open in windows photo gallery, then open it in "paint" again, then go over and click "Image" at the top bar, go down the menu to "resize/skew" and click that, then when the window pops up, type in "75" (%) vertical and "75" (%) horizontal resize and then click "okay". The file will now be downsized considerably and should be well within the size limits of the forum software. Actually, you can upload large .jpgs to TRF and the forum software seems to resize them for you, but YORF and RP does not, so if you're posting the same pics over there, you might as well do it the "old fashioned" way and downsize them manually. For VERY large pics (over about 1.2 MB in size, you may have to compress them again, using the same method again... open the .jpg in paint, click 'image', click "resize/skew", and type in "75"% again in BOTH vertical and horizontal boxes (otherwise it'll stretch the picture out of shape) and hit "okay" then "X" out of paint... compressing a second time will certainly get it down into the 250-350 KB range, well within the upload capabilities of the forum software.
You can either keep the .jpgs since they take up less room on the hard drive, or you can toss them after you're finished uploading them and keep the .bmp versions as 'full res'. Usually I just keep the .jpg versions and put them in the appropriate folder...
It SOUNDS like it takes a long time to do, but it really doesn't... once you get used to it, you can do a picture in about 15 seconds...
Hope this helps!
Later! OL JR