I remember in 1994 a friend had purchased OS2 for his 386dx with 8 (!!!) mind blowing megabytes of extended memory. OS2 took nearly 18 minutes to get to an interface you could use - not to install, to boot. went back to DOS lol.
If it was OS/2 from IBM it was true multitasking and the OS in full control of memory allocation, something Microsoft only were able to offer after creating a new operating system from scratch (Windows NT).
If you thought OS/2 took forever to boot on a 386DX with only 8MB of ram, imagine how long it would take to boot Windows NT 3.5 on that same machine....
Windows NT came out of the failed collaboration with IBM and was originally meant to be OS/2 3.0. MS switched the APIs from OS/2 compatible to Windows compatible after Windows 3.0 took off, and it caused the collaboration to fall apart.
Are your talking about the ibm version? I liked it and it was great for work because it could really multitask. I had a pretty good system though so no really long boots. my issue was that it couldn't handle any gaming, so back to dos for me as well. crazy that it's been all these years with windows, some good some bad, and now windows is shooting itself in the foot just as Linux is becoming a system that can finally handle anything.
I used it in a necromanced college laptop... 486DX2 at 40MHz, no L2 cache, but admittedly 20Mb of RAM. It was slower to boot than DOS, but reasonably usable. By 3.0 they included half-decent pack-in software, while Windows still had just Write (not even Wordpad)