Is it safe to use 2 to 3 way outlet plug adapters?

I think it usually is.

Does your computer have any warnings or directions specifying otherwise?

@Brian1946 All my computer info is scattered around the apartment… I’ll never find any of it… but when I had it it didn’t say anything about outlets

The only equipment that I’ve seen with a warning not to use a converter is my washing machine.

How about Googling something like, “Computer make, model electrical requirements”, ”...warnings”, or ”...safety precautions”?

I can’t really tell you from my own computer set-up because it’s 3-way all the way.

No. Be sure to get some sort of surge protector, too.

It is safe if you hook it up correctly. US and Canadian AC plugs are polarized and most of the items we plug in are polarized too. That is why one blade is bigger than the other. Also some devices ground the case through the third post (the circulate one that farmers, like me, cut off because we were too lazy to install 3 prong outlets out in the barn.)
If you bought the adapter in the US it will have either a green wire or metal stab sticking out of it. That is so you can attach it to the screw in the center of the socket. That will become your ground for the third post. Do it. Then you are good to go.
If you are not sure if your wiring is correct you can either measure the voltages or use one of those handy outlet testers with the three lights for sale in most hardware stores.
The surge protectors need all three wires hooked up to work correctly.

@worriedguy The key word there is correctly. Most of those adapters I’ve seen do not have that tab hooked to anything, so they are not grounded properly.
That ground is most important for equipment with exposed metal that may become electrified in the event of an electrical fault inside, like many power tools and pieces of kitchen equipment. As most computers have a metal case, they qualify as well since there is a slim chance that an electrical fault in the computer could electrify the case and pose a risk to personal safety.

@jerv Exactly. Most products sold i the US have polarized plugs. The neutral side, white wire, goes to the larger blade, while the hot side goes to the black wire on the smaller blade. Products made for use in other countries do not always have this arrangement. For example, Japan does not use polarized plugs. The appliances have isolated cases and plugs that are ambidextrous – both blades are the same size.

When I moved in to my older house I checked all the outlets and out of about 50, two were wired incorrectly. Hot and neutral were reversed. I quickly fixed it.