If you just saw a clean install of Windows go on simply download and install from the adobe site's download page. Adobe - Downloads It's about as safe as most other programs in that sense.
Typically when you need it to view a pdf file online you may see a prompt with option to bring you to or simply download and install the latest version. I've never run into any problems with having it on here.
If you are looking for an alternative reader Sumatra PDF is a good alternative. It does have some limitations however as far as creating and editing new pdf files. Sumatra PDF - Download
In most cases you will simply find adobe reader is required when going to view any pdf files like mother board manuals, specifictions, etc. online. As far as the update prompts you will see for the next latest version that will automatically remove the previous for the new.
W7 Ultimate x64/W10 Pro x64/W11 Pro Triple Boot - Main PC W7 Remote PC Micro ATX W7 Pro x64/W11 Pro
CPU
AMD Phenom II X4 975 Deneb 3.6ghz - 965 2nd remote pc
Motherboard
Gigabyte GA-790XTA-UD4-Gigabyte GA-880GM-D2H remote pc
Memory
Kingston Hyper X DDR3 1600 1.5v 16gb - Hyper X Fury 8gb 2nd
Graphics Card(s)
MSI HD Radeon 5750 1gb - MSI HD Radeon 6450 on mini tower
Sound Card
Creative Labs X-Fi Xtreme Audio P - Realtek onooard 2nd case
Monitor(s) Displays
ASUS VW199T-P 19" HP 2082a Main-HP 2082a 20" remote pc
Screen Resolution
Asus 1440x900 - HP 1600x900
Hard Drives
WD Black 1TB HD per OS W7, W10, and pending W11 presently on 500gb OS Drive - Pending Triple 1TB HDs for Spanned Storage/backup volume
Single 2TB external USB enclosure, single 1TB System 7 Host/Boot drive, Pending 8TB external HD for system image b
PSU
Corsair 750TX - primary / Corsair CX600 - second
Case
Antec 900-2 - SSD compatible / NZXT Vulcan mini tower