Anja; Older system like 98SE were made at the time that USB was just to be born. For your PC to recognize a device, apart from working device being in correct physical contact to PC, it (PC) has to have the knowledge to understand what that device is. This is called driver. Every device has its specific driver for specific OS, that is not interchangeable. Now many new device manufacturer, assuming that their customers are not in use of older OS, won't go to trouble of writing driver for every death or intensive care unit residing OS (98 included here). For eg Canon assumes a consumer who uses win 95 or 98, will still buy their film products and won't go digital....
If you are interested (And don't expect spoon feeding) you need to google your problem or make searches in Microsoft and canon sites. Here is a link to start:
LINK USB problems in Win98
As for checking what version of windows you posses, it is very easy; On XP in the run box or its equivalent on older OS such as 98, the DOS commend box (That black board appearing icon that I think was in "Control panel" or in accessories, just type " WINVER " this is not case sensitive. On hitting enter you have all info needed.
Next Don't even get to trouble of running Canon's programs under 98, instead please just listen to me and buy that CF card reader. The reason the seller told you, you can't find it, is because the guy was stupid enough to think you mean only the older single CF that are probably absolute by now. All you need is "Memory Card Reader" or what now a days is called "All in One reader" that support Win98 (You must ascertain this by reading the box of this device for compatible softwares). If you are in Canada, you should have no problem buying goods from US, so here is one like that sells one such device that virtually reads any kind of camera memory you and your friends might own just for under $10:
LINK
Scroll down to Additional information and see that under PC requirements, it is 98se compatible.
Now after first loading the driver that comes on a CD along with this reader, You elevate your PC's knowledge (Needed driver) then when connecting the reader to USB port, you will see at least 4 many be more drives with E F G H etc designation. It is peace of cake to drag and drop the images form say drive F (Ducan's favorite) to the C: you hard drive. Please just do it with out much farther questioning unless down the line you have some Qs. But for about $10 this is your best option.
Now if you truly need my advise, Win98 is RIP. Don't waste you time much. You no mater what, need your own new PC and if you can afford to have XTi, you must be able to afford an entry level PC. In fact I just recently got across a deal on new Dell PC with Vista home edition and a lot of blow and whistles for $399. A better deal in Laptop was for $599 (You don't need monitor, everything is compact and by its wireless receiver there is 100 percent chance of finding a free hot spot to go on line (BTW I don't mean your insecure neighbors net work, no no, me no bad advise...I mean you can take it to local coffee shop, restaurant airport likewise that provide free wireless internet, should you need it, if the local connections are not a choice as for eg yahoo's fast DSL or cable or verizon or ATT are about only 14$ a month...). If you get to the point that want to avoid headach and need a new Vista operating rocket speed PC, PM me for links of hot deals as I encounter them often but for best deal you must be willing to wait and then once deal available, act fast.
Cheers and hope this helped.
BTW the other rule of thumb about computer age I forgot, is that some pcs are female (Just like French language that everything has feminine or masculine feature, If you are from close to Quebec you know this better than me) and as a universal mater of obligation, they simply refrain to accept new numbers for age but well you know when you checking compatibility, speed etc, just like wrinkles, we don't get to details etc, they are not really what they claim...
